One of the actual reasons manga can be better than certain American comics is that it is creator owned.
Once I picked up Death: At Death's Door and asked about it. My comic guy explained how popular Jill Thompson's other efforts with the Endless were and that this was a new story for that audience, etc. "Ah," say I, going on to summarize, "sanctioned fanfic." It has finally percolated through my thick head why the answer to that was pretty much a grumble. Also why this is a particularly ironic title to say that about.
A great part (it's a good store and I couldn't say if this is over or under half) of the content of the store could be summed up as "sanctioned fanfic" or, worse, "solicited fanfic". The characters in so many books are corporate properties written and illustrated by the page by someone who did not originally create the world or the character. All too often by someone who would rather be working on something else.
The stories add on year after year until there is far too much life lived for one character and something happens (cue Superboy!) so that everything can start over again. Besides, the inconsistencies from having so many cooks were probably starting to add up.
Creating something new seems to be anathema. If a new character is needed, often an old character is recycled instead. Pick one off a back shelf and give it a makeover. Or, better yet, find one that is still active enough to have a following so there's a built in audience! There's a laziness about it on both sides. The publisher doesn't have to pay a new creator and the audience doesn't have to go looking for new interesting characters because the stories about the ones they've found already never end.
There can be good stuff to come from this. The Sandman series, from which the book I'd picked up derives, is, I am given to understand, work for hire. A long forgotten character completely reinvented for a pitch and the publisher had the good sense to agree. (That other guy who wrote Good Omens is really a rather good writer whatever he goes after.)
There is plenty of chaff as well. Personally, I find the sudden appearance of a character who just happens to be owned by the same company but doesn't usually seem to be in the same sort of world stomach turning. Your average creator can tell which sets of characters should be interacting and doesn't mix them up, your average company full of corporate owned characters sees a quick buck in giant crossovers between groups and no one can stop them because they own all the trademarks. (I don't know how this gets them the bucks, but apparently people buy it.)
Of course it all ultimately comes down to the writing. A bad writer may have a better chance of it if handed the ready made setting and populous, but there really is no need to coddle bad writers. Meanwhile a good writer can be susceptible to all the world crossing, cameos of favorite characters not involved, and whatever else that is the mark of fanfic and not of good stories.
