I don't feel the same way myself in PtbA games, because there are so many potential hard moves you could make, and they could range from stuff that's going to just make things a bit harder, to things which make things vastly harder or virtually impossible. I haven't DM'd BitD though, maybe it has a much narrower range of hard moves allowable? With stuff like DW though I always find myself holding back - not going for the maximum adversity, but rather what is going to make things interesting/scary/exciting/funny.
I understand what you mean re: jacket though. Oddly I felt 4E D&D was best for that, because in 4E, if I balanced an encounter properly, I could go absolutely all out and try to do everything I could to kill the PCs with the monsters I had available, yet everyone would have a good time. Never before had an RPG really offered me this opportunity. In earlier editions of D&D, if you went all out, you'd simply TPK the party sooner rather than later, because the encounter-balancing was either non-existent (1E/2E) or so bad it was literally worse than non-existent (3.XE - the CR system there is literally more misleading than eyeballing it). 5E is mediocre at this. It's not actively bad like 3.XE, and the systems provided are a bit better than just eyeballing it, but you can't just do things right and then go all out unless you <3 regular TPKs. You don't need to fudge rolls or anything, to be clear, just not go for maximum adversity tactics at all times (to be fair this often lines up well with RPing the enemies anyway).
Fair enough, I misremembered that. They still half-arsed it by not having SAN reversed when making ability checks though.