I really don't see any difference between a vote that's explained with a useless "nn" and a vote that's explained with {{nn}} which expands into a paragraph-long genereric dissertation on the subject of notability. Typing those curley brackets doesn't require any extra thought and provides no extra information.
I don't regard nn as useless so I have no problem with them amounting to the same thing.
-- geni
Whether a particular article topic is notable or not depends on the topic itself can't be explained in a single template. If you're going to say an article is nn, at least the nominator (or if they don't the first person to agree with them) will need to explain why the topic is not notable. Just saying "Delete, nn" or "Delete" agree with nominator" when the nominator themself wasn't clear isn't informative.
As the professor article shows: 1) Nominator said subject was boring (not a proper criterion) and non-notable (without explaining why). 2) The other unanimous delete voters either agreed with the nominator, call it vanity or didn't comment at all. 3) The subject was a professor with published books on his name which precedent says are keepable.
People can be away and not visit AFD for a period of time while still caring for the article, but simply not being aware of its existence. That doesn't mean no one cares about it. And while unanimous and in process, it's still a wrong decision to delete something as being vanity or non-notable when precedent clearly shows it's untrue. Had I known about the article when it was originally up for deletion, I would've voted keep with a detailed explanation based on policy (with links).
Also, I'd like to reiterate a point made above: if you don't have the time to explain your vote, don't vote. AFD is a discussion page with the aim to get concensus and not a majority vote. When you vote, you should make an informed decision about the article based on its content and show it to the closing admin by explaining your vote. Admins are not clairvoyant and one could easily be vote stuffing, if you don't explain the admin can't see the difference.
--Mgm