Totally agree. I've been fortunate enough to avoid any major issues so far.
It's possible that only the people who originally signed up for the iOS public beta can access it. I remember they limited the number of people originally, and dont know if that got expanded.
Yep, as far as I can tell, it is only available for the people who had submitted bug reports during the Yosemite public beta period (as in, they used the beta for the purpose of which apple wanted them to).