I don't exactly agree with your concluding theory the amounts are far too low and so are the amounts you're able to buy in chips every in-game day. Yea, sure, if you play enough, you'll probably eventually hit at least one of the middle 12 numbers, but what you're seeing here is variance call it 'bad luck' if you want, but it happens and chasing it when you're on a bad swing is how people go broke and how the casino stay open and profit.
Roulette as a whole doesn't exactly have the best odds for making a profit at the casino. However, when it comes to gambling, nothing is exactly a guarantee. Are you talking about the middle 12 numbers (13-24)? If so, 31.6%.
