What's to say that those they saw weren't junk? It's the same as for you to say yours is great. The idea that rifles using recycled parts from a company known to cut every corner possible, it seems pretty likely that some will happen to have good parts and others to have mangled parts.
Look at the S&W M&P15 sport. $600 with a rifle with new parts from a company with a great reputation and quality new parts. CMMG bargin bin gets you a new rifle with new parts for $600. A delton rifle kit, a stripped lower, and a set of punch pins will run you $525 or so and again be of known quality new parts. If you are willing to spend a little more, you can get into a Spikes or BCM rifle, both of which have shown to use high quality parts and not skip many corners. If you want accurate you can get into a WOA/CLE upper and a complete lower for around $800 or so. That's not to say your rifle won't work well for you or most others, just that for similar money you get something with a MUCH better reputation and for a little more money you get something with a HUGE reputation. Why would you risk it on a CAI rifle even if it looks good from the start? Its a vastly competitive market right now with everyone making a rifle. Picking from the guy with the worst reputation seees like a risky move at best, even if some/many are coming out made decently well.