It is a service of a site if they decide to pay the fees for a payout. I also think a site should do that better. This costs a lot of money on an annual basis, but you want to keep your customers satisfied.
I also do wonder whether it will still be possible to deposit at Adkinsbet with other payment methods. Skrill and Neteller, for example, are very popular.
ya.ya.yo!
Probably they will not implement payments like you oppose. The idea for Crypto gambling is to stay as anonymous as possible. If you will introduce the alternate payment solutions, then that idea is gone.
They could consider it to offer for people who wish to. If a user chooses mBTC as currency, then you can only deposit and withdraw in cryptocurrency.