If there weren't bet frames, people could bet at any point throughout the match, which would take away from the purpose of betting.
I think you mean why people aren't allowed to bet after the valid bet frames? The answer is simple. It's to avoid people who only bet for profit when they're sure that the person they're betting for will win.
Basically, betting was made to test your luck. So, if there were no bet frames, it would be pretty one-sided
Yea I don't get it either. The betting makes more sense to me if they can only be placed before the first turn or before the second maybe but I'm not sure what effect this would have on how people would bet and the frequency of betting in server etc.
The host can easily change the betframes to something smaller to remove the issue you stated but they just don't. :/
Another possible solution could be introducing some maths to the betting system to pay higher to people who bet on earlier turns where it could be said that the match outcome is less decided. I might try out hosting a low bet frames server sometime soon just to try it out.
Klein Bottles only have one surface so they are the easiest thing to clean