The public beta program is still strange to me. The seeds as they stand are still quite buggy but in obvious self-evident ways, ways that don’t need hundreds of thousands of ordinary users to test the OS and report back. If Public Beta members do report bugs, I am sceptical that they bring up new issues that Apple’s internal QA team or the developer community hasn’t already found at this ‘early’ stage in the cycle (seed 3).
Also, I’d love to see data on how many people running the public betas even bother to use the Feedback Assistant at all. I think most people that join do so just to be part of the ‘cool’ club running prerelease operating systems. They don’t have the motivation nor technical knowledge to post useful bug reports. Most developers don’t either.
Running a public beta program is a huge endeavour, especially when you consider the additional costs on Apple Support when something goes wrong, for what I see as little upside.