Yea... If that's true, it would create bad image and reputation for exchanges who're doing that; ripping the traders of the stakes that should be theirs, whatever the volume...
ccex has that image permanently since VNC story,
they simply calculate what's more profitable - fees or staking,
when deposited volume is enough and there's a risk of losing huge profit -
coin gets put on maintenance, nobody cares of reputation there,
of course they keep good relationships with devs of such coins

I see... Thanx for the info