Actually I am using bitcoin for those gambling sites that required bitcoin to be paid in order to get stakes, if the gambling site required other coin to be used in order to get stakes to play in the gambling session then I will convert my altcoin to bitcoin or vice versa, it really depends on the gambling site on what coin they are using in order for you to get stakes.
As what as you said it is good that there is a gambling site or platform in order you can use other cryptocurrency in order to play in their gambling site.
I guess in many online gambling sites, besides using bitcoin, they have more options for an altcoin to be used as the bet. So I think you can choose the other coin than to use bitcoin only. But if you still prefer with bitcoin, then that will be no problem at all. Sometimes they also used their own token as bet regard of they want to promote their project to people so they can reach more investors to invest in their project.