The BoS, Enclave, and NCR are not individuals and cannot be judged by the same standard as a single person.
-I don't see any diffrence. NCR is supposedly there to help and protect. Supposedly they are the "good guys". That actually makes it worse. Even more so for the Followers.
And I don’t necessarily mean medical tech. Think of all the other good House could have done for the area, but instead he was fixated on maintaining “his” version of NV and his own power.
-And this is diffrent how from NCR, BoS, the Legion, the Followers, the Kings, ect? Do they not all pursue their own agendas? Could they not all have helped "the salt of the people" more than they do?
And I agree, “evil” is a little strong – but “evil” as in "I murder people for fun" is an extreme rarity. Morally “grey” people do most of the evil in the real world.
- I agree. Morally gray people do most of the Evil. But who defines evil? Who defines white? Things are rarely clear cut, good vs evil, black vs light. We have computer games, books and movies that present us with nice easy to digest nuggets of good and bad and thats great in fiction. But in the real world (which IS how you should look at a RPG I think) things are mostly shades of gray.
For instance, most here sell all of their drugs, hoard all of the caps that they can, buy armor and weapons they really do not need ect, when they could donate the drugs to the followers, deposit the undepositable drugs where they did no harm, they could kill off drug suppliers, they could do all sorts of things... but they do not. Does this make them evil? Nope. Inconsiderate, narcissistic, arrogant, greedy, ambitious, murderous (after all... we kill our way through the game, some for the nice NCR armor, for that non-drop brushgun, some only when they have to) and many other things, but not evil. Only the roleplayers play evil. The rest are just in it for the nice pixels and the achievements. But if you apply how you would think of them if you were "in game" and don't "metagame" you soon come to realize that things are not very clear cut if you want to roleplay. And House is roleplaying.

He is roleplaying the guy who puts every single resource and all of his logic toward his vision of post apocalyptic vegas. Just as the other factions do.