Recently many countries around the world are now introducing gambling taxation on it citizens and even charging betting houses and casino's some amount of money to operate within it jurisdiction, and recently my country just introduced a 5% Revenue sharing and taking from both betting houses and gambler's winning and this news make me to ask why the government takes such money from gambler's but won't protect the gambler when their is troubles with the betting house.
Because we have loads of cases where gambler's win some huge amount of money and the casino refusing to pay and when reported to the authority you here such things like the casino is not licenced by them or they don't have control over the casino case, the government is only interested in the tax and not protecting the interest of it citizens.
You seem extremely mistaken if you think that governments do not regulate gambling - they absolutely do and for good reason. Gambling had been used throughout history by criminal elements to launder money, because it is an environment where people can come in with loose cash and have it cleaned by trading it for casino chips. They are notorious for this activity and it drew a lot of attention from law enforcement, so they are not heavily monitored. There are also plenty of laws around gambling, who can do it, where it can be done, even if they are a bit looser on where gambling can be advertised these days. Governments are also reactive, so if casinos get too greedy or push the boundaries, there is often push back and law changes to tighten it back up again.