I think their Joes are generally of very good quality, though. It must vary from license to license somehow, probably based on who they think is buying.
Joes are made to appeal to, in general, an older and pickier audience, whereas the main audience for the Marvel figures is probably little kids, who won't care. So, Hasbro lets the cheaper, crappier factory in Hong Kong produce those.
Have to say, I've seen a total of one kid in a comic book store in all of the years now that I've been buying comics. One, and he came in, bought a Pirates of the Caribbean comic, and left. Frankly I don't know how well the twelve and under crowd can follow and appreciate comics these days. One line I would never have thought kids would begin to wrap their minds around was T-bolts, my personal favorite, the characters from which are now dominating the Marvel U. I don't see kids grasping the storylines and having a great familiarity with situation and vocabulary concerning the events transpiring. What I like about comics today is how adult they are, and how they don't pander to a young audience... which undoubtedly wouldn't be able to afford comics these days (I have a hell of a time setting aside the necessary cash for my favorite issues). That's Marvel, and with DC any major event requires knowledge of far-reaching backstories which a kid who just picks up a comic casually I don't think would understand. Atrocitus prying open a man's ribcage to spill his blood in a voodoo prophecy to read the secrets of the present and future; Norman Osborn crucifying the Swordsman and savagely beating women; Bullseye murdering civilians including children with nothing but relish... saying these characters aren't gaining attention because they are geared to kids whereas GI Joe is not just isn't a pov that holds ground. Granted, I still bought comics when I was a kid and was reading things I didn't wholly understand nor appreciate at the time, but it got me exposure. Kids do buy comics, but the crowd who goes to the store religiously to grab the newest issues and dumps out wads of cash on the counter, are, I think, largely the 20s-40s crowd, the people who I see there every week.
Though I have to say regarding DC opposite Hasbro with Marvel, DCD does a great job of churning out quality figures representing the characters, and which collectors and kids can both appreciate in equal fashion.
I'm not a Joe collector, but I can understand the nostalgia; I just think that the design for Joe figures is tried and true, going faaaaaar back through what Hasbro has done over the years and hasn't changed. Their JP action figures were of the very, very highest caliber for the first and second films... but when the third rolled around they were producing tinker toys for children, not figures for collectors and kids alike. I think that most of Hasbro's lines today are utter ^^^^, and Joe collectors are fortunate not to have to worry about decline in quality. If a company that regularly produces ^^^^ creates a new line at the height of their ^^^^ empire, you have to expect the product to again be naught but ^^^^. Enter this Marvel line. God I hope they turn things around. The preview shots looked awesome, just not digging the in-hand figs.