Thank you all for your reasonable explanations.

My very own opinion, those mechanism could be ok only for beginning levels (say, 1-3) whose "managers" have not been familiar with the rules and system. I am quite sure that the guy in my case has already left T11 since he was at level 5 where all his players' quality is not higher than 45, and many of them have been out of the contract. But with the auto-generated players, who are based on level 8's quality as at his level, this leaving manager has advantages (even maybe he has no idea about this because he was not interested in T11 long time ago).

I think, that IS the unfair point!