I tend to look at how polarizing the experience is more than “oh man, this thing has a 52 vs a 53% aggregate win rate in the meta!”
Handbuff paladin is one of those decks with a play pattern that most decks have basically zero response to. It’s not great when you load into one and your only real chance to win is that they completely brick draw.
Yes, there’s a few things that are popular right now that can beat it, but that doesn’t really excuse what the deck does.
People just don’t play it enough for it to get nerfed. Both decks.
They are monotone, one-dimensional, boring and create a sense of a lack of agency, as you’re literally just hoping to draw a weapon and then toss minions on curve and pray it’s enough
Not to mention it has 0 RNG other than draw rng.
BORING, BORING, BORING
They probably think that nerfing Paladin will make the OTK/combo decks too powerful. I mean we know they love their no mana decks that explode for a win all over their opponents. So they probably want Pally to stay there as a placebo for players that they can point to in countering those decks instead of fix the problem they themselves created. I don’t really know how else to explain this weird meta.
And yet, people flocked to elemental decks, where you don’t even have the weapon or handbuff part 
Well, here are the differences, though:
Elemental decks are control-ish, and people like playing control decks, as it gives them sense of agency/options (except Mage, that one’s literally as you described, like Pally)
It’s also kinda cool to finish off somebody with disgusting dmg for 3 mana. I know, because I play Sludgelock and it can become addictive xD
And last, but not least, Lamp nerf came too soon for people to get bored with the decks.
Handbuff pally is also very controllish. That’s why they run those rushes, including the lifesteal one. The weapon having lifesteal itself is really important. Some lists run Tarim not just for his offensive potential but also the mini for control.
As for options, handbuff pally actually has lots of options, technically more than elemental decks since elemental decks are limited to elementals with utility, whereas handbuff can run technically any minion. Not every handbuff pally deck is the netdeck version. Some do excavate. Some run tech cards like cult neophyte or that card that makes cards that didn’t start in deck cost more. If they run zilliax all handbuff pretty much run the modeul that summons another copy, but the other module could be double attack for more aggression or perfect module for control/long game.
3 mana lamp is cool? Ok, then surely a 1 mana pirate is even cooler. Better yet, give the pirate windfury with the 3 drop which is cooler than bouncing lamplighter since we’ve had bouncing for years to the point I’ve seen some cry for shadowstep to be rotated out for a change.
As for being bored for being an old deck, that’s just personal feelings. As above, some people find bounce boring. The entire priest class caters to a playstyle that’s not for everyone. In the past people would cry about tickatus lock even when it was a tier 3 deck, because people just hated their deck being burned so much (this probably extends to boomboss)
This makes me think you’re confusing two decks to be one and the same - Handbuff and Reno
I could be wrong, but I don’t think I’ve ever seen a Handbuff Pally NOT run a doubling dmg double zilliax.
Anyway, I’m kinda sick of discussing Handbuff Pally xD Been doing it for days in 2-3 different threads, and the deck isn’t even played much!
I’m done here xD
That part was responding to your comment that elemental decks have options. I’m pointing that pally have more options since pally can choose from a larger pool of minions than simply elementals.
That you would call them different decks actually illustrates my point. There are actually enough options to create entirely different decks.
Is there a version of handbuff pally that 99% of people run and that deck is boring because you see the same cards over and over with no different options? Sure, but that’s more about netdecking. People choosing not to run different options doesn’t mean there aren’t options to choose.
Netdecking works xD
I can’t build a deck from scratch, but I can swap 2-4 cards and make it better. Many people can. And that means that all those better options have been tried, and kicked out, because it wasn’t working.
Doesn’t mean it won’t happen, when something changes (sort of like other decks had to replace their Discount Zilliax for Double one due to last patch)
It has subtleties. E.g. you can ruin some confident mages or rogues or similar “generators” if you start carefully playing and buffing your Razorscales or Custom Enforcers; not all players think correctly of those things; that’s because they may wait for too long to first handbuff them but it can start being done very early.
But I agree RNG is pretty comfy in that deck; I’m not saying it; the stats are saying it since they have very similar Drawn and Mulligan impacts unlike most other decks that have brutal imbalances even on DRAWN (which implies they are REALLY sensitive to bad sequences of draws).