Is the perfect like deponency?

(Like all headlines that begin with a question, you can assume this one should be answered with a negative)

Randall Buth noted that across the history of the Greek language the idea that the perfect is imperfective is totally novel and for that reason it should be suspect.

Con Campbell concluded the discussion about the perfect this afternoon with the response:

Well for the past 500 years deponency has been accepted as a valid category.

Surely he knows that Robertson 100 years ago didn’t like the category.

More over, most pre-1900 grammars have no consensus on how to define deponency. As far as I have found, the concept of ‘active in meaning; middle/passive in form’ didn’t appear until James H. Moulton’s introductory grammar of 1906. So the claim really doesn’t hold.