Indeed, there are some people who hide their gambling from other people because they do not want to burden other people (the family) if they lose.
So people also hide their gambling activities because they believe that if their family members know that they are gamblers, they will really be mad. There are some places where gambling is a bad activity, and they see gamblers as bad influences. The amount some people waste on gambling is kind of high, and if their family members are going to blame the person if they know the amount that's been spent on gambling, I'm sure that's another reason why people keep their gambling activities secret.
Apart from that, it is indeed difficult to understand if other people think gambling will have a bad impact on ourselves and others.
Some people are against gambling because they believe that with time some people might end up getting addicted to gambling, which is very bad because at the end they will end up doing things that they are not supposed to do, things that will spoil their reputation in society. That's why some people are against gambling, even if the person is not yet addicted to gambling.
You could say he is looking for security not to tell other people about his gambling because other people may not be able to accept and understand what gambling is.
For people who don't like gambling, they think that gambling will use up all their possessions, but on the contrary, the opinion of people who like to gamble is that they partly hope that luck will win here, and they are comfortable doing it.
In fact, if we can control ourselves and be careful when gambling, then we will not be addicted to gambling.