I don't know. I kind of like the fact that even once I've got all my rooms sorted out and hit the dweller cap that there'll still be something to work on. Annoying as it may be not having the "perfect" dwellers short term having that push to find +7 Wasteland Gear and train new dwellers up using it and replacing old dwellers just keeps the game going for me.
I like it as it is. It's a bt unfortunate we had to discover it instead of it being immediately known, but I like uncovering new tactics and strategies.
I don't understand why so many people seem to think you NEED to kill off all dwellers that do not have max HP. obviously you wouldn't want them on the top couple floors fighting death claws but I have plenty of level 25+ dwellers with 2 - 3 end. that can kill rad-roaches and put out fires just fine. Mole-rats can be tough but you can design portions of the vault to be mole-rat proof pretty easily. Move your starting and legendary dwellers to the lower levels and put your max End. dwellers at the top. problem solved, no reason to kill off anyone. If you want to kill them off and replace them with stronger dwellers you can but it isn't required for success in this game
As for not knowing about End. affecting HP from day 1...Every fallout game I've played has been this way. when i first started I wondered if this game was "smart" enough to track their health per level up based on End. I was not surprised to find out it did. This should have been a loading screen tip but it wasn't. We had to actually play the game and figure out how it worked...Anyone old enough to remember playing a game before there was an internet full of info and forums.
I do feel for the Iphone players who had maxed out their vaults before the deathclaws were introduced but all they need to do is kill off about 12 dwellers and re-level them with max end and its problem solved. No need to start over or kill off everyone. This isn;t a bug and the game plays as intended. I'm an android player. I was lucky enough to come here and read about the deathclaws before I hit 60 dwellers and was able to make sure my vault was ready for them.