Yup, there's reason behind why gambler wanted to hide his activities, some because or religious or cultural belief while for some they are just ashamed being tag as most of the time people who look thinks that your participation already judged you as an addictive gambling practitioner. Though, it's always the person itself who can justify and answer the question.
In this case it makes sense that a gambler may hide their activities as it can be very difficult to deal with the scorn you may receive simply because you enjoy an activity other people do not like, but this is what makes online gambling and even more specifically gambling with cryptocurrencies such a nice thing, as now you can be incredibly discreet about your hobby, and unless you make a colossal blunder or you tell someone else no one will find out that you like to gamble.