This is too simple for my idea.
My ideas is, once you go to a gambling site, deposit your money and place a bet, you don't go "ah well, that's that let's just move back to normality"... You keep gambling (sure you might have a stop win and a stop loss but inevitably you will probably go back to the site and keep gambling).
Go back to the 1000 users of my example, and for simplicity I'll make it 1024 users with 0% house edge. Assume they have a perfect distribution of winning and losing, and they keep playing "double or nothing"!
This is what happens:
Round 1: 512 winners (2 BTC each), 512 losers (0 BTC each).
Round 2: 256 winners (4 BTC each), 256 losers (0 BTC each).
Round 3: you get the point
.......
Round 10: 1 winner (1024 BTC), all others lost all their money.
Now remember, this was at 0% house edge.
In reality: If the casino has a 1% house edge, it takes 1% of the total wagered amount on each bet. That means, each round, the total balance owned by all remaining players gets slightly lower.
Now imagine a casino with negative house edge, that means the total players' balance increases with each bet they place. It doesn't matter if players are greedy or not: bad luck can bankrupt them instantly, and good luck can multiply their balance a thousand times or more. That can happen with a positive or negative house edge.
A player winning a lot isn't a problem to the casino, as long as the house wins on average. For that, it has a house edge