Withdrawal fee in gambling site?

I am with sportsbet.io from long time and they do not have any withdrawal fees. With cloudbet.com, they also do not have fees. With onehas.com, they do not have withdrawal fees for the first withdrawal in a week.

I did gamble in few other sites (nanogames and few I can not remember), not much but withdrawal fees was never a thing I seen. It's an immediate discouragement for me. I also dislike the exchanges, the amount they charge (0.001BTC or 0.0005BTC, it's just too much).

To answer your title: I think there should be a Zero withdrawal fees like sportsbet.io. They can give a minimum withdrawal requirement though.