Is stingers still a merit source?
Not anymore. That's clear abuse, awarding merit for political reasons rather than any idea of quality. Only because he was a source, I effectively undid those merit sends. If he had not been a merit source, I still would've blacklisted anyone who got into DT1 through that type of shenanigans.
Regardless of how justifiable it is, this is not helping your "I wanna do this hands off" argument.