imho the beta testing shouldnt be randomized, some people are better at beta testing than others, maybe they should have every aspirant beta tester write a small paragraph of why he/she wants to be a beta tester, some people have no ide of how frustrating the life of a beta tester can be. if you're beta testing your own code it's even more frustrating, I can speak from experience there
beta testers should not expect to play a game, they should expect to play something which looks like a game but is actually a collection of bugs, definetly in the earlier stages.
Also, I doubt this would happen, but some bugs are SERIOUS, as in: damage user data. PoR had a nasty bug that survived beta testing and ended up in retail which removed all data from C.... effectively formatting your drive, nice, really really nice ...