It's not a new idea. My main problem with it is that it reduces the trust the community has in admins as a whole. Admins can only do their job if the rest of the community lets them, and the rest of the community will only do that if they trust them. Having a way for people to get admin tools without the strict processes of RfA would diminish that trust and make the whole project unworkable.
To summarise: Adminship is not about being trustworthy, it's about being trusted.