I don't believe there is any such thing as an unspoken rule of calling something "lazy design" that changes its meaning to anything other than "lazy design".
I think making idle complaints about the B15 damage is lazy. Before I go on, I can save a lot of you a lot of time and sum it up like this - there's always a way to improve, a way to account for aliens getting harder or XCOM getting weaker, and Impossible being savage is what drives us to make those improvements, develop those new strategies, refine and innovate out of necessity rather than settle on one unbeatable strategy and stagnate.
I've seen those kinds of complaints from a fair few people since it was introduced. I feel like we tend to forget what picking a hard difficulty on XCOM is meant to entail, myself included. Compared to vanilla, Long War is really forgiving and generous in its early game missions. I think we get so used to that we forget that sometimes, the bad guys get lucky; and as they say, the good guys have to get lucky every time they go out, but the bad guys only have to get lucky once. XCOM has never, ever been about people only dying when you make a mistake. One of the best things about Long War is the fatigue system forces you to build an actual roster - usually I'm not a fan of such a wide-reaching change that totally forces you to play in such a fashion, but it was absoloutely one of the best features to introduce. And I think we forget that why it's so good is that people die in XCOM! The point of having a 40+ roster is there's another 39 angry troops waiting right there to get payback.
War is absoloute hell. So is XCOM, as it turns out. I'm just speaking for myself now when I say I often forget that - and I think that in itself says a lot for how safe and complacent I've become in Long War. I've discovered strategies and squads that very rarely see a death - hell, even in my most recent TMX, one of the worst days of XCOM I've had in a long time, I only lost three troops - and every one of them was due to a mistake that, in hindsight, could've been avoided. Prior to that, I'd only lost one troop, again in a way that could've been avoided. Isn't that still too easy? If you can make it through Long War on the hardest difficulty there is without even having to worry about your luck running out once or twice - aren't we spitting on the graves of every XCOM Trooper on the memorial wall when we have this entitled expectation that Long War should be so safe and fair to us as long as we don't make any huge mistakes?
War is absoloutely a dangerous business, and XCOM's situation is one of the most dangerous I can imagine. People die, and there's drama. That's what makes XCOM, XCOM. Sometimes, your favourite soldier gets grenaded out of cover and killed by a Cyberdisc. Sometimes, it's not even going to be your fault. Sometimes your favourite tanking infantry just gets crit for 15 in half cover by a Muton, and it won't even make sense why. And sometimes you'll do the same back to them. You have to pick up the pieces and move forward. Anything less, and there's no inherent risk, no tension, no constant sense of dread that is such an important part of the atmosphere of an Impossible run.
What JL said is very true; I think we expect XCOM to be this perfect puzzle game where you do the right moves and get the S Rank with three gold stars. But that's not at all what it is, or what it's ever been. It's bloody, and sometimes good people die for no reason. You have to account for that, prepare your roster for that. But you also spend all your effort to avoid it for as long as possible. You do everything you can to mitigate the bad luck, and you play your best to stave off the reaper from your troops, mission by mission. Most of the time, you'll succeed; sometimes, you'll fail. And rarely, sometimes you'll do everything right but get kicked in the balls anyway. I think that's exactly what Impossible difficulty should be. And I don't think there's any problem with that, because if you as a player don't personally like that, there are lower difficulties. I think many of us who choose it, or at least I know I have, come to just see Impossible as the defacto difficulty. But it's not the official 'way its meant to be played' - its the hardest. Shit will happen. The game may even be unfair - and it would have every right to be.