Yeah, this bothers me a lot. I also don't really like that it isn't instantly attributed to being a "grognard" either. I'm only just about to turn 21..so IE games and the like are all nearly as old as I am, there is absolutely no nostalgia in them for me, rose tinted glasses, found memories of things of the past, etc because I didn't start playing any of them until I was around 15.. so only 6 years ago.
I WANT strategic enemies because it's wait for it.. strategic (shocker). You can have things like enemies that are resistant/weak to certain magic types for example without it breaking the game as a "gotcha" moment. If only one character can use the one skill to kill that one enemy necessary to advance the plot I would agree, that's stupid sucker punch material.
HOWEVER, just because there's an enemy encounter that can be plowed with a magic weapon and you don't have it for whatever reason, as long as you can still progress (just with a little more effort needed) that's not a sucker punch.. that's fair. If you want it to be easier, go back and get the skill,item,weapon,whatever to make it easier and if you don't care put up with the slighty harder challenge.. nothing wrong with that type of game play in my opinion.