I kind of look at it this way..
I worked with Nanner on Generations at War as a member of the team, did a lot of work.  Some textures, scaling, a few kitbashes.  I've worked on close to 400 models.  Have a policy of if some thing I worked on is ported to something else.. please send me a screenie.
I should be drowning in screenies.  Think in five years, I had KF send me some, and got a few here of ingame shots.  I gathered some from the BC forums (none were ever sent from there).  One, I think, was sent by a Vegastirke player once.  Oh, and I had something ported to Starshatter.  That's all I know about.  But I imagine that there's lots in Armada, lots in BC, maybe even some floating around in Legacy and Solar Empire.  Dunno... don't have screenies.  And I imagine that people claimed credit for my work as well.  But I think the bigger issue is not the posters, I think it's societal in a consumer driven society.
(gulp) more please (gulp) more please.  Probably not even that, more.. (gulp) (hunt) (gulp).
But I don't know if you can blame anyone, or expect anything.  I go by downloads these days as well.. and I occasionally hope to see screenies.  But I don't expect to see comments, and when I do.. I'm happy to see them.  I like to get constructive criticism because sometimes it points out obvious stuff I've missed.  (How many windows on the TARDIS?  Geez..)
I think the number of models we're still seeing is frankly astounding.. I love the fact that we're still seeing stuff for SFC, and I still enjoy doing the work.  It'd be nice to see more comments, but personally, I'm glad to see any..