Bots would destroy the betting game.
Everyone would use bots and force all the average to weak players out of the game.
In the end, there will be only bots left.
Well then, I guess that creates another market opportunity: figure out what bot/program a player is using, and design one to counter it (or download one, if you can't be bothered). In the end, you might end up with a programming competition, rather than a chess match.

Oh come on. An avid chess player could beat even the most powerful bot. I'm pretty sure that chess is one of the hardest board games to "exploit" with automation. [...]
Tell that to Kasparov - where have you been these last 20 years?

Chess is a perfect information game (that is, a game where both players have full knowledge of the complete state of the game), with relatively few movement options - perfect for computers to play, and win, against humans. Furthermore, their capabilities only improve with each passing year, alongside processing power and changes in programming techniques.