If someone set too small fee that makes his transaction get confirmed in a very long time then it is user's fault why he set too small amount
Technically, you are right
However, this is not how things are going to unfold in real life. People complaining here and elsewhere would still hurt the public image of the casino. You are not allowed to set your own network fees on most exchanges (in fact, I don't know about any where you can do that), and this is considered normal and standard behavior. In other words, doing it differently would be too risky, while benefits minuscule provided there are any at all
It wont hurt the public image of the casino, at least there are some casinos has this option where players can set the fee based on its priority (Low, Med, High).
With this option, I do believe gamblers prefer to use Med and High priority because they want to get the transaction confirmed fast.
I havent seen any complains on those site with this option, crypto gamblers are getting smart time to time so I doubt that gambler will choose low fee as they are aware about the consequence.
Of course it is just a suggestion from yahoo, the idea is to let players set higher fee than the default one set by the casino.
Sometime fixed fee which is being paid by casino is smaller than the recommended fee, this makes players wait longer time for their own money.
If there is an option to pay higher fee, then players wont need to wait for longer time for their money.