A nice new change of scenery does seem more fun then sticking to the same old same old. And I think some players see club play more as for fun and experience. The real rewards are with their NT. But I guess it all really depends on the type of player you are.
It also shows how good a club really is if you can win with a different set of roster year after year.
I don't agree, if things are working what's the point of changing. To me, dramatic changes only make sense when the group is unsuccessful, which is not the case for Vakıfbank. Moreover Vakıfbank's success relies on their stability. In last 10 years they only change only 1 or 2 players from their starters opposed to Eczacıbaşı which changed their whole starting 6 almost every season.