Millhouse Manastorm - practically, no players play it
Hemet Nesingwary - you don’t need a legendary card with subpar stats, just to destroy a beast. Even rare (blue gem) cards have better options for destroying, say, a murloc. And it comes with better stats.
Nat Pagle- sure, it was nerfed. And since then, it effectively became a zero-player card.
Of course only Blizzard has the stats. Why don’t they share the stats and rationale?
Bad cards are always going to exist, just like there’s always going to be good cards too, i don’t really think it’s a problem to have some bad legendaries.
Also, there’s always a chance at least some of these could become viable in Wild if some amazing synergy is added, maybe a card that removes battlecfrfies is created as a tech card, well now Millhouse is your anti-tech card, or a card that interacts with zero attack minions that makes Nat good again, I’ve seen cards i thought were terrible become important cards in good decks quite a few times.
OP
2 things
“Bad cards are ok” is a limited-time excuse.
Meaning, you can only have a small amt of “bad cards” for the “Bad cards are good for balance” argu to hold up.
Once that cloud gets more than a handful on it, it collapses. HS’s “bad cards are good for balance” legendary-cloud has been overswamped for like 3-4 years.
Most bad legendaries are too expensive to not-affect-the-board.
Classes have a hard enough time drawing and surviving to synergize two cards same turn to get them to do something, so 1/2 or more of the classes, such as hunter, can’t play two late game cards together reliably, bc you know draw and survivability.
See in life especially business, people like to say “change management is hard, its the hardest thing to get used to”. Same things as “bad cards are good for balance, its just change”. The truth is “bad is ok” is just that, a big excuse to sound-right.
“Some bad is ok” is totally accurate.
“too much bad is not-ok-at-all” is also accurate.
HS has way too many ‘bad’ legendaries, usually due to being > 5 mana and not doing anything on board where your opponent decides if it can live or not to take effect, a big no no in design unless that class can reliably set it up or has good draw, or being cheap like MH or Pagle that require several cards to synergize with it, on top of it being drawn early, for it to matter.
Legendaries have a mega-penalty of being only 1x, making them a lot harder to use consistently / find on curve.
So OP to correct your post you should add “and most 5+ mana cost legendaries” to your options, like option-D.
Make sense?
Just understand “Bad cards are great for balance!” is only true when there’s only a handful of bad cards. When there is a medium amount, or medium heavy, or heavy amount, the whole “well, bad cards are good for design” excuse shows it’s true colors like it has. No disrespect to Jeff, he is most likely pointing out the good part of “bad cards are great for design” which is yea, a handful, but not this many.
Also OP, HS has bigger card-problems than legendaries, such as draw or sustain for hunter, or aoe that isn’t combo, or draw to find those combo aoes overcosted utility cards and such.
Most the time in HS the problem cards (for being too weak) are white / blue / purple, without the backbone, the legendary isn’t in your hand, it isn’t being synergized with etc.
I remember being able to use millhouse against one of those heroic Galakrond’s awakening bosses, by him copying the one in my deck and playing it, making my spells free.
I think the scariest legendary to have is The Darkness, because if it got summoned somehow, that’s a minion slot permanently lost.
The devs have brainwashed people here by twisting the concept "bad cards are healthy for design. Which is true, but intentionally ignores that those bad cards don’t need to be unplayable. Everything is relative and bad cards will always generally exist as long as good cards do There is really no excuse for a card that you spent money to obtain is so unplayable that you can’t even use it in a deck even for memes.
So what do you suggest then that needs to be done with all the weaker legendary’s ?
And why do you consider those legendary’s are a problem right now ?
Do you want to buff them all and then some of those buffed legendary’s will be even better then some of the current ones right now so your argument becomes a loop.
And what stats do they need to consider ? overal play rate ?
Lackey summons 2 cost 4/4. Bad card? I think not
Yeah yeah there should be no bad cards ever. There should only ever be 15 card total in the game at any time. That way there is only 1 possible deck ever so that mean no cards can ever be bad because they are the only cards.
Wouldn’t people just argue that Blizzard is trying to bleed us dry if these legendaries were good?
Sounds about right. Either Blizzard is scamming players because there are too many bad cards diluting the card pool, or they’re scamming players because too many good cards means more expensive decks.
To be frank I’d rather have good and bad legendaries in the game because otherwise the dust price to have a somewhat competitive collection ridiculously balloons if you actually need to have all the legendaries and not just the few good ones to play the game.
They’ve brainwashed themselves.
Too many bad legendaries is 100% a factor in deciding whether to buy packs for me. It’s a disincentive. You know that even if you spent $70 on the 60-bundle, there’s a risk you’ll get no decent epics or legendaries. Why would you?
Whatever nonsense they want to feed the average forum user isn’t going to change how their actual customers feel about handing them money. Spending money and getting nothing doesn’t feel satisfying. Blizzard only lose themselves profit by hiding behind excuses.
Actually, x number of legendary must be released per game and having bad legendary cards just take up your chance of even getting decent legendary cards. Your logic is therefore wrong.
I see Millhouse in hand, I play it. Don’t even close my eyes to play him 
Actually millhouse was already part of an extreme overpowered deck.
Even paladin.
Cheat out an 4/4 was worth the risk of the dead draw.
Only 1 instance to support this argument? Really it’s not substantial enough
Well, bad cards are healthy for design. Of any card game. There is obviously a limit, if every card were terrible apart from a handful which were amazing - that would be bad design.
But there’s no brainwashing… bad cards are healthy. it is just a fact of card games.
If anybody is interested, here are two (lengthy) articles on the subject which explains virtually everything regarding ‘bad cards’. (They’re MtG articles but the premise is applicable to any card game).
I can’t post links apparently, but just type in to Google ‘mtg why are there bad cards’ and it’s the very first two links.
Edit: the links are called ‘When Cards Go Bad’ and ‘When Cards Go Bad Revisited’.
Use the `` marks (one on each side) so your text looks like this and you can get around the link restriction.
To summarise the article:
You look at the 2 cards. When have, or when will these bad legendary cards ever see play, realistically?
Ever seen sustainable play? no.
Likely to? no.
So yeah, they didn’t explain this part.
And not all cards need to.
Nat Pagle, one of your examples, I have used in many decks with varying levels of success. Just because you cant find a use for him doesnt mean no one else can.