I'm not willing to pay excessive costs to prove myself right. Bear in mind that social costs are still costs.

I'm also not willing to impose excessive costs on others as part of proving myself right. Consider that if betting becomes widespread, it may have the effect that poor people are locked out of intellectual circles.

I'm also not willing to take excessive risks to prove myself right. If I have a 95% chance of being right, but the loss for the 5% chance of being mistaken is large enough that I'm risk averse about it, I'm not going to make the bet.

Some of those reasons are perverse incentives. For instance, if I am going to bet on X, that gives me a financial interest in not convincing people of X, and in weakening my arguments for X. (That's not in the posts, but it is in the comments.)

Furthermore, if I believe X,I don't need to bet on X to convince myself of it--after all, I believe it already! I'd be making the bet to convince other people. Needless to say, many of the problems with betting directly relate to convincing other people.