They can also hide because other places are public and it is prohibited there. Even when I was studying at an educational institution, I remember a story about how several guys played poker in the library and they were expelled for it. After such harsh methods, none of the students dared to repeat this. These players that the OP is talking about didn’t go home to play with one of them because they probably had parents at home, or their sister might have told their parents about it. Generally speaking, they simply did not find a better place and did not want anyone to notice them or interfere with this.
The main reason is family, that's all. People who start gambling will hide from their families. they didn't want anyone else, whether their friends or neighbors to know they are a gambler, because they didn't want their gambling activities to ruin relationship with their families. When it comes to regulations, They can easily skip them. they can play at home, right? But why they are hiding from their families, because they doesn't want his family to know about that. so they are tried to hide from anyone who knew them. Family factors are the dominant factor why gamblers hide.
Among my family, of course, no one knows that I play gambling, except for my sister, who also understands a lot in this area and we have common topics, and we also support each other if we have losses. But for example, I definitely don’t want to tell my mother because she simply won’t understand this, she doesn’t have the experience that I have for many years, and of course she will form an incorrect assessment of me. I might have told her, but I’m just sure that it’s better not to do this so as not to cause her additional worries about me.
Gambling is often frowned upon in society, so some people hide. And we should not forget that the legislation of many countries prohibits gambling just anywhere. For this purpose there are strictly designated places and only in them it is allowed to play. This applies equally to online and offline games. It is unlikely that anyone would want to break any law, so just in case they prefer not to gamble at least in public.
I literally remembered an example from Thailand that I saw on TV today, betting on cockfights is officially prohibited there, but people still do it and it attracts a lot of gambling men. And the most interesting thing is that the police do not deliberately disperse them, maybe for the better; many people need to let off steam after hard work somehow