That’s because.Wow, I can't believe how many "beta apologists" there are out there.
Seriously, this isn't a June-beta or July-beta. This is a beta that went out mere weeks before the final release. This is not the kind of thing that you should see when the release is imminent. Yes, it doesn't crash. There's no data-loss. But it's still extremely annoying, and casts a shadow over Apple's quality control process.
Wait for it....
Drum roll please....
.... it’s beta!
Of course there’s bugs; regardless of version. There’s no ‘shadow’ being cast. And Apple engineers don’t read Mac Rumors forums - so don’t think your words mean anything outside this echo chamber of amateur users. If you don’t like bugs, don’t install beta software. Simple.