Rock, I don't quite understand what specifically it is that you don't like. If in the game it's easier for you to kill oponents(and thus easier), isn't it easier for your opponents to kill you(and thus harder) which balances things out? I'm thinking one of two things:
1) Perhaps you're not challenged because there are more low/un skilled players playing the game now than before(which seems obvious - larger pool, only a certain % can ever be highest quality) and so getting a match with the same number of similar high-skilled players is more difficult.
2) You're pissed off more by the fact that otherwise mediocre players who would never have been able to touch you before can now have a reasonable chance at a kill and the skills you developed over a long period of time are diluted by the game's engine(a FPS version of old coot's syndrome - (lol) everyone uses guns now, any idiot can use a gun, but back in my time you had to learn to use a sword, and let me tell you...)
Seriously though, I think that it's just the nature of evolution and every sport/game goes though it. Tennis, baseball, football, hockey, bridge, chess, tv, video games, take your pick. Every so often something new(rule, equipment, etc) is introduced for some benefit(you listed some of them) and some of the purists always argue that the fundamental sport is changed....and perhaps it is, but you can live in the past(nothing's stopping you from still running a quake 1/2 server) with it's hindrances(nothing new in the game) or live in the present with it's hindrances(too damn much new in the game) lol....