Bitsler is not a scam, let's make that clear though.
If their wallets are filled with small inputs that can cause transaction fees to go higher than normal just because their minimum withdrawal is really small, then obviously they are going to set a higher minimum. Plus i'm sure the minimum was there before ETH was even pumped, meaning that they haven't updated it according to fiat values.
In addition, as far as I know, they pay the transaction fees for you. And what are you? Doing microtransactions especially in gambling like dice? Even if you go to other dice gambling you will encounter the "minimum withdrawal" thingy. I just hope that you don't report them here one by one just by that.