Kicks would be poo in public lobbies but would be fine in private ones. If lobbies are implemented, there should be two kinds:
Private, where the host controls those who join and kicking is possible. These lobbies should not affect leaderboard points, either.
Public, where the host can't control who gets in and kicking is not possible. These should affect leaderboard points. However, users can't choose which public lobby to join, although one can form a LD party with another few users, which puts the party in the same game when joining. It should not affect teams, however (could lead to abuse if a few good players are on the same team all the time).