I have seen the same, people are complaining that the fees are too high and it is taking a very long time to get a confirmation and without it they cannot gamble at all, while some may not consider this to be a problem if you are looking to make a transaction with a low amount of bitcoin it is entirely possible the transaction cost is going to be bigger or at least be a significant part of the value you are trying to send in which case it does not make a lot of sense to send that money over to the casino.
You are right, the transaction cost is another issue, but, as of recent, paying $2 to $3 worth of bitcoin as fee is not bad at all to transfer $100 or more, this is the range of low transfer fee for now, within 2 to 3 hours, the transactions will be confirmed. But, if the people not satisfied with that, they can make use of altcoins like litecoin as payment.
This is why if you like to gamble it is a good idea to have a small stash of altcoins that have very cheap fees and that you can use in the case the bitcoin and the ethereum network get really busy, litecoin and dogecoin are good options for this, especially dogecoin which not only can get you a fast confirmation but the huge amount of dogecoin I get for my bitcoin makes me feel I am betting a lot of money when in fact I am just betting a few dollars.