So the country you just came from would have to offer VOA or VE or else you couldn't fly back, right? Unless you have a multi entry visa with time still on the clock.
If people are denied entry at an airport are they forced to buy a ticket all the way to their home country? That is what would make it an unacceptable risk for me. If they let you fly to the country you just came from and it's a question of a $100 ticket then that is an acceptable gamble, for me at least.