There is no lack of online trading, if you have the nintendo online sub you can very clearly trade. It's a core mechanic to help people get version exclusives. 

if you shoot me in the face in black ops you ruined not only my kill streak, but you also ruined possibly me building up to scavenger pro which fucking sucks considering that i don’t play cod 24/7 like most people do and i don’t treat it like we’re going to make it to a pro scene because most people wont.

the people who ruin shit really comes when you are trying to unlock pro perks in the older games. try unlocking scavanger pro as a new player in black ops JUST TRY