People these days want to be the best at everything they do (which is not possible).
I think the old days of PS1 and PS2 when you just had campaigns with no online play, but you could buy the cheat discs which had something like 40,000+ cheats on them are half the reason for the rage of today.
People would buy these disc and play the game in god mode, unlimited ammo, etc etc and they always won no matter what so they got into the "expecting to win everything without trying" mindset.
Online is different, you don't always win, you CAN cheat but risk a ban and people hate to lose.
So what do people do when they feel bad? They make other people feel bad to make themselves feel better, I think they call it Low self esteem.
I used to make up some classes just to annoy some of the people running around with an SMG Lightweight and Extreme conditioning or just about anyone for that matter. Believe it or not the rage was flying within 2 minutes of most games I played using those set-ups. As I am not a stat person and don't give an owls' hoot it was fun to watch the better players rage at my "so called" cheap tactics. It also made them re-think their game so in a way it did help them to change their mindset and tactics. One player even thanked me for making him see that he doesn't have to run around like an Ostrich on speed. Lol