Would aftermarket injectors eliminate the problems encountered with factory units? I personally don't care about a warranty if I have to keep bringing my truck in for the same problem. I just want it to work, period.

no, the aftermarket units all start with GM cores

Is it me or is there a huge market out there that nobody has exploited yet?

Maybe in a couple of years. Almost all Dmax units out there are still under some kind of factory injector warranty. I don't think there many '01 / '02's with over 200,000 miles or '03 / '04's with over 100,000 miles.