With fixed odds, there has to be a limit to the amount of tickets
that can be sold on any combination. The house wants a guaranteed
profit. In the lottery every number has the same chance as another...the
state knows they get a 50% cut, and that's that.
In Jai Alai, the house cannot pay off true odds on a rare combo if there isn't enough cash in the pool. And even if there was just enough in the pool to do so, only one person would be able to play that number. Can you imagine how pissed off people would be if they weren't allowed to play their lucky numbers with the hope of making a score. Let's not forget that many people in all aspects of gambling have no clue or interest in true odds and probabilities.
The house is leaving nothing to chance. If you like a combination...say a common one, 5-2-4, you will often be told by the seller that the number is already sold out, Not only will you be pissed off, you'll realize you may as well have stayed home and played the lottery.