Not being able to BETRAY in Halo 4,5,6 just Suicide???

How About not being able to not betray at all in halo 4,5,6 Betraying is one thing;But like on reach you get a accidental betrayal and you get kicked for 10 minutes come on,how about no betrayal in halo 4,5 and 6 just suicide???

You should still be able to betray people, but I never understood why Friendly Fire was never turned off in MatchMaking. I mean how could that really be a negative effect?