Both of the ones I named: WoW and ESO have kick timers. WoW's is 30 minutes. ESO is 20 I believe.
Anyway, it's beside the point. Every person that is logged in takes up resources. Whether you are paying or not is irrelevant and always has been. If you aren't actively playing the game, there is no reason for you to be on it. If you got kicked off, so what? Log back in. It takes no time at all to do so even during prime time.