gambling is often seen as a harmful habit. my question to you is, in a completely free society, should someone be prevented from providing gambling services for the good of society?
First, if we are talking about a completely free society and the government allows gambling establishments, there is no ground for people to prevent someone to provide gambling services, may it be for the good of society or pure business intent.
from an individual point of view, it is everyone's choice to gamble or not to gamble. the management of your money is entirely up to you in a physical sense. but that doesn't change the fact that some people are going to go bankrupt, their lives are going to be very difficult with the existence of gambling. if it was up to you to allow gambling, knowing that it is inevitable when enough people are involved in gambling, would you consider it ethical?
In subject manner, anyone can consider it ethical and unethical. For me it is in between depending on how people engage themselves in gambling. If they are responsibly engaging in gambling, I consider it ethical but if they are gambling irresponsibly then they are gambling in an unethical way.
do you think that things that can harm a person through their choices should be prevented, or is everyone responsible for their own decisions as long as they are not forced to make them?
Yes, things that can harm people through their choices can prevented that is why there are laws and regulations, and through suggestion and advice, but ultimately, the person's action is dependent on his own decision alone.