yeah, sites tend to have one or the other. the ones i know of that have both either integrate them so she share a single back end to save on resources (IE: comments actually being forum threads that are getting transposed onto sections of the site outside the forums, and it's the same login for both) or one drowns out the other and people start ignoring the one they use less.
If it comments ever get brought back, the 'forum integration' option would probably be better in the long run. It'd take more to implement initially, but having one system instead of two would likely eat less server resources, and i can see a shared login acting as an easy entry point from one to the other.
Most important thing I've learned from D&D?
No matter how tempting it may be, as a DM I can't both present a problem and solve it.
Every time a DMPC or NPC fixes something a payer couldn't i'm diminishing and undermining that player's contribution.