And what’s written on it? If it explicitly states something that matches your description, what’s the problem with it?
It’s actually not that bad: you’re essentially guaranteed at least a rare merc in each pack, until you’ve got them all. As for legendary ones — yep, that’s more like winning in a lottery.
Surely, someone who isn’t an avid critic or an ardent hater is a ‘shill’ and a corporate slave — there’s no such thing as objectivity. 
Even that is a repetition of what’s been said above, though.
If you don’t like packs (which is understandable, since all kinds of loot boxes have drawn much criticism — and who does, anyway?), I’ve got good news for you: this game mode, unlike e.g. Standard, is very much playable without opening any packs at all besides those you get for free from story and mercenary tasks. I’ve personally bought a number of them with gold to blow off some excess of it, which I would have nothing to spend on anyway, but that would only serve the purpose of getting a couple of legendary mercs from the latest batch faster (I can’t say that they are dealbreakers for PvE either — maybe for PvP, though; on the other hand, I could have crafted them with coins from just doing the new bounties anyway) — the bulk of my collection has been built up as described above, including crafting legendaries (I started fishing for them in packs only when the latter started to accumulate from tasks). There has been, however, a negative trend in this regard (or increasing greed, if you will), which I’ve written about (and others have noticed this obvious fact as well, see, for instance, another video by OG [1] on the subject, apart from the one I referenced earlier) — so it’s hard to say whether the game mode’ll stay that way, i.e. as F2P-friendly as it is. Currently there hasn’t been any cause for optimism in this regard, but we don’t know yet how the acquisition of Blizzard will impact things.
[1] https://www.youtube.com/watch?v=8NMRrVBfVkg