Yeah, people have talked about DD and his character in the various episode threads rather than just the dedicated Charlie Cox thread. Punisher doesn't have any episodes yet.
Also, people were already subscribed to this thread before the Punisher forum was even created, so I'm sure this thread from the DD forum is the one that keeps popping up in their user panel instead of an equivalent Jon Bernthal/ Punisher one from the Punisher forum, and people just continue the discussion here.
Of course, if the mods moved some of the discussion from here into the thread in the Punisher forum, then people should be automatically subscribed to that, and they would probably continue there.