And there is the problem, the general public wouldn't know a quality AR if they fell on it. It's precisely why NEA, Dlask, Norinco and others continue to sell their wares. The average owner shoots 200 rounds a year from a near sterile environment and never gets the gun hot or dirty. They think their low round counts equate to a "reliable" rifle when they don't. They also think a deep even anodizing is the sign of "craftsmanship" which it is not and that the lower the price the better the deal.
Milspec is just that a SPECIFICATION. If your rifle isn't milspec then what spec does it adhere to, are there any specs at all? Not saying milspec is the be all to end all but it is at least a standard that can be used to measure/gauge the level of quality materials and craftsmanship involved. Feel free to enjoy your unknown quality rifle just don't spread BS about it being "just as good as" a known quality brand alternative.
As for 16" carbine gas guns, yes they're dumb. Read a book have a look around, midlength gas is a superior system to carbine and is doable on barrels as short as 14.5". Carbine gas is simply what was used on M4 carbines and is easy to duplicate for the commercial market. It works but is grossly over gassed which increases recoil and wear on parts. The end user(the US military primarily) doesn't care about service life nor the cost to repair/replace them which is why they don't really care if the system is sub optimal. The commercial market also doesn't care because they only sell the guns they don't maintain them. Then again why would a company look into improving performance of their product when they can sell sub standard rifles all day long..
So milspec is required for rifles you don't like but doesn't matter for rifles that you do. Explain to me again how you're not showing a double standard?