Who are these people you hide your gambling activities from ?
Give a reason why you don't want them to know you are a gambler.
It's like with Bitcoin, only a couple of people know that I play poker or that I have Bitcoin.
First because it's frowned upon, and I'm not going to bother to take away the bad reputation, and second because they are activities that involve money. If I were to tell people that I have Bitcoin, maybe word would spread among criminals and I could face a $5 wrench attack, even though I am not a multi-millionaire. Same thing with poker, if word gets out that I am a winning poker player, maybe word gets out and some crooks interpret that I make as much money as Negreanu, with all the danger that entails.
Since it has more potential disadvantages than advantages, I don't say so.