This is actually protecting the players somewhat, because these casinos don't want to conduct business in a country where gambling is illegal. There are some countries on the list where gambling sites are actually blocked completely due to government isp level censorship, so the user would only be able to access them by using VPNs. If the Philippines doesn't have that and is able to catch players through isp logging, it could lead to criminal prosecutions which can be quite severe in some of the more religious states. It's better if players are just warned off from the very beginning.
If the casino doesn't allow gamblers from any particular country, the Philippines in this case, then it is better to avoid gambling there. Even if people can sign up through VPN, they will still have a hard time doing KYC. Even without KYC, it is risky to gamble at that casino because if the casino identifies that you're from a prohibited country, they can close your account and may cease the funds present in your account.
However, if the gambling site allows your country but the country does not allow gambling in general, then one may use a paid VPN and may not be caught by the legal authorities. However, one needs to be technically sound on VPN usage else ISP can still trace him.