Each to his own, I guess. None of mine have ever given me any problems. That's 5000+ rounds each through 2 of 'em. If they were that bad, why do they get snapped up right away on the EE or any time a gun store gets one? I admit, I would much prefer an original Sterling, Howa or Costa Mesa built AR-180 myself, and if we didn't have ####head-engineered gun laws in this country I'd own one of them rather than a 180B. However, if you like 180's (which I do) you shoot what you can get. They incorporate a simple, short stroke piston driven mechanism.
I shoot coyotes and rabbits with mine. I can't do that with my AR-15's (of which I have 2 of). Can you?
The snap ring for the front take-down pin.... I guess that is kind of goofy for a rifle that should reasonably emulate a military-grade rifle. However, there are parts in aircraft and other large pieces of engineered machinery that thousands of people rely on every day for safety that incorporate snap rings. They're a very common component in many pieces of machinery. So, while they are kinda funny on a rifle, I don't think it's necessarily a bad thing.
The plastic lower.....thousands of firearms carried every day by police officers and soldiers all over the world are made of polymer. If you don't abuse the 180B (especially at the front hinge) it will never break. At least mine never have, and mine aren't safe or range queens.
Will the 180 or 180B ever be an AR-15? No. I don't even compare the 2. My Bushmaster and my Colt are far superior rifles in construction and craftsmanship. Their design has also been refined for half a century with U.S government financial support while the AR-18 was designed with a different purpose in mind and then the design was abandoned. They are a completely different rifle and I don't pretend my 180Bs are AR-15's.
I suppose haters are gonna hate.....