Composing, however, is something that cannot be artificially speeded up....
While I agree that high quality songs should regularly make sales in the long run, I disagree that you can't learn to compose faster and still compose well.
There are plenty of composers who score films in 3-4 weeks. Sometimes that's over 120 minutes of music and, although some do reuse old material, being able to compose quickly doesn't necessarily mean your work will suffer. In some cases, I'd say it actually improves your compositions as you have to get the job done to a strict deadline so naturally focus considerably more on the task at hand.
The only point of making production faster is an attempt to spam the marketplace with frequent uploads in order to leverage the front page exposition.
Spamming this site is only possible if the AJ review team allow it as there's a vetting procedure in place. If you think 'spammy' tracks are here now (however those may be defined), it's because it's been welcomed in through the front door and given a glass of buck's fizz to join the Envato party.
I've heard some composers say their best-selling track took them an hour to write in some cases, so for me, it really is about when the track is 'ready' rather than how long it takes to write and produce it. Also, how simple a melody line is has nothing to do with the quality of the track in my opinion (listen to the Social Network soundtrack, which is simple yet works very well I think). All that said, I usually can't write a track in an hour and be happy with it, but that's a personal preference.
While both you and I probably agree that there should be fewer tracks (and of higher quality) in this marketplace, it's partly because we want our own tracks to be found more easily to boost sales. But library work has two approaches that lead to success from what I see and from what seasoned composers in this area have told me:
1) The first is mass-producing tracks that are over a certain threshold of quality so they are suitable for purchase. Some composers have told me that you need over 1000 tracks in some libraries to make regular cash as that's what is needed to be found and purchased regularly, particularly as prices drop and competition rises. I don't like the idea of that at all, and I suspect you won't either, but there is some logic behind it when you look at the maths and it's certainly an approach that a lot of composers take. We are told to continuously upload after all, so big portfolios tend to appear as a result.
2) The second is to be extremely focused on creating a few very good commercial tracks that work for your niche market and sell well on the merit of hitting the zeitgeist (among other things of course).
This second scenario is the ideal in my opinion and works well for some authours here. I kind of wish I'd taken a single-niche approach when starting to build my portfolio as I went for the varied genre approach.
However, option 2 is a tricky route for new and future artists because of the rising number of tracks in this catalogue. I've found some incredible authours with small portfolios whose tracks are great, but they get lost in the sea of new tracks / competition.
You may have noticed there's a strong correlation between successful AJ authours (often with small portfolios) and successful Video Hive authours - that relationship will only become harder and harder to forge over time for new artists and, I think, relies on a great deal of good luck.
Unless you are so unique and have no real competition (Gareth and I were talking about this in another thread with reference to Tim McMorris), then marketplaces get crowded so you're not going to get found as easily. Getting quick at creating and mixing your music can only be a good thing in that environment, particularly if you want to make a living making music professionally as you'll need to be able to compose very fast when the client clicks their fingers.
That was a long one, sorry for the rant!
PS, something that I think is worth adding (albeit off-topic) is that, like any marketplace, we should be constantly adapting to demand. While we learn to write and produce higher quality tracks (whether that's quickly or not), we should also be learning when to trim back unsuccessful ones over time. That's kind of like a third 'half-way house' approach to composing for libraries I think, essentially distilling your portfolio down to only your best work over time.