It's for your own good, because that version of plus! may be unstable... not because plus! is known to be unstable, but because it's like the first running of it. Beta testers who test it know the consequnces of what could happen like in extreme case, loss of data etc. So if you're running it, it could crash etc. and you could loose stuff. It's best to wait for a final version, because it should be bug free. The beta testers will be prepared for bugs...