It's obviously a balance, but you could use that argument to allow any plugin on the store. It gives more choice.
I think it's important to remember that while PushBullet is known to many of us, is posting on Hacker News, is a valued part of "the community" in some respect, at Google scale this fact is not know. PushBullet is obviously good to _us_, and maybe just needs to tweak permissions a little, but to a reviewer at Google it probably looks very similar to the hundreds of extensions they may review a day, many of which may contain malware.
They have to use certain metrics to sort the good from the bad, and abuse of the permission system – intentional or not – is a pretty good one when you care about the end user.
I often wish for a separate browser for consumers that are also devs. I'd happily lift the permissions for some open source extensions I'm using if that means better functionality.