I really doubt people suicide nading are worried about their stats ... they do it for the giggle factor, the upset.
If we're going to start restricting in some fashion things we don't like ... that will open a can of worms.
What I can't stand is sneaking out of spawn, no enemy around, and BOOM you all get taken out by an RPG round that was launched from on top of the tower.
Another thing that annoys me ... is the ability for people to be on top of enemy spawn with sniper rifles. Talk about stat gobblins!
So, in summary, I don't play for rank, obviously ... wouldn't stop me from blowing myself up to get the sniper out of the window or the such. If you know war strategy, it takes sacrifice for the good of the team.