I do agree with your opinion, but then, let's assume that BetFury has almost every Altcoin listed but does not include usdt, and they don't also have any other stable coin listed, then their listing is sure not complete, they are better off delisting other Altcoins and keeping just bitcoin, BFG and usdt listed.

Reason is because, some gamblers who like to deposit and withdraw in bitcoin, also like to play games using bitcoin, while others like my very self prefer to deposit and gamble with stable coin, which is usdt, as this helps me to keep proper track of my profit and loses long term. While there are those who like to deposit in random Altcoins, those can maybe buy BFG and use it to gamble on the casino.

So, regardless of how many Alts the casino lists, usdt or any other popular stable coin is very important to keep listed for those who love to play using stable coins.