What the author is describing is a 'Martingale' strategy, and it is indeed a surefire way of making a profit (with one critical caveat: you need an unlimited bankroll).
After each win, you always earn a profit of X (where X is your base bet), regardless of how many rounds you have lost before.
Without a sufficiently large bankroll relative to X, however, probability of bankruptcy is high.
I bet 50, and lose.
I bet 100, and lose.
I bet 200, and lose.
I bet 400, and lose.
I bet 800, and lose
1600, 3200, 6400, 12800, 25600, 51200, 102400, 204800, 409600, and then...
The reason they have limits is so that Sheik Abudab can't come in and lay down 500 million dollars and bust them. That is one valid reason to take bad odds: If you can destroy something as a side effect, without really being in danger yourself.
But now that I think about it, you could always just move to another table with a higher limit. Of course, if you're going through all this trouble to make $50, you probably don't have the bankroll to keep going.
Maybe another reason for tables having different limits is that the pit bosses don't trust the dealers (or security?) in the low-roller areas to handle money above a certain amount?
That doesn't sound very practical. And why play roulette for money (rather than just for fun) if you already have unlimited money?