Kicking players?

I've become game admin (for the first time) in a game that had a massive drop-out. I think we have like 6 active players left in the entire Africa-map. I considered kicking the inactive players to see if it would attract new players, but the game says I shouldn't do that without the players consent.

I think that makes no sense. Ppl drop for a reason and surely will not reply to my messages about if I may kindly kick them out of the game they allready dropped?

How does everyone else handle this?