I remember back in the day that was the norm, people would distribute their earnings when they get a huge win, of course not all of it but like 10% of it so that people would cheer them, there wasn't really a big reason for it, some people initially did it and it became a gambling cultre in crypto world, just like in real life when you win big you tip the dealer even though you do not have to. But, after a while in many places there was "hidden" usernames started and people just stopped paying when they made a big win and just hide behind their usernames, which I guess they have a right to do.
I have never really earned much from the rain on bitvest but it is okay since I do not really chat anyway. People there all know each other and it is hard to get in and find someone to reply to you except occassiaonlly the nice mods,,, but good to see that this is a good way for people to earn. Me I just gamble and quest. Lately invest not so good but time is needed:)