Sounds snobbish to me .. "yes our CF scores lots but he doesn't deserve to play for Ajax"? If a manager makes a player look better than most people expected (top scorer in league, multiple CL goals), I view that as a positive. No-one who saw him at West Ham expected it.
He also said doesn't play enough youth.. I'm not saying he found these players (that's not his or any Ajax managers job) but playing Onana, De Ligt, VDB, FDJ (who'd all have been about what.. 18-21 in ETHs first season?) sounds like playing some youth to me. Your goalie, a CH and two midfielders (probably others I dont about).
Plays Haller "too old, not good enough". Plays young players "expected". There hasn't been a successful club in history who played all youth, even ours. Having a manager who gets a good balance and makes players look better than expected .... that sounds like a positive to me.