Well, to keep on track with LEGO it's important to balance a budget
It's positive effects for me are just that it makes me happy. It's a fun hobby and like all hobbies they are meant to be enjoyed.
Of course with all Hobbies there are those who take it too far and become obsessive, like your example of that man.
I can understand that it could fill a void in someones life, but of course alot of things can do that, some worse.
LEGO when taken in moderation, is healthy for anyone.