Why should corporations be granted permission to carve off valuable and generic domain mindshare for their own agendas?
One could argue "You couldn't register .blog or .dev before, and now you can't either, so whats the problem?"
Well, the issue would seem to be that it's reducing the possibility space for everyone. Indeed, there are other competing applications that would in the future be open to all, but will not come to pass, if this closed corporate capture goes ahead.
One last point to consider, why can't Google apply for .googdev or .googblog?