Oh look, the little shit is alive! That said, I believe they're -restricted- because of an anti-cheat. Most aimbots use +Left and +Right to snap on to desired locations on a player model. I believe that's the reason for it, so it's just there for security reasons. It doesn't change anything for me since I've rarely if ever used them.
I believe it was more because I was purposely trying to trigger as many false positives as possible for Drogen's detection plugin (so we could get more accurate triggers). Use of +left/+right allowed me to trigger hundreds of false positives in a short amount of time. That being said, why do people need +left and +right? I'm not some super amazing try hard so maybe I just don't understand but I have never seen the use in them.