I would have to say the lack of understanding what people with prior knowledge are telling you is irrational. I took interest in this thread and have read it through out. From what I read you "hypothetically" think all parts are created in the same place, welded by the same weldor, and built to the same quality control and thus Rusty's should be equal to any other, and are unjustly accused of shortcomings.
Obviously this is not the case, and thats where the issues come into play. A prime example of your lack of understanding is in the bushing statements. Just because two items look very similar does not make them of equal build quality. I have seen a kit car that "looked" just like a Ferrari, but was a Pontiac Fiero with a really nice body kit. You are probably saying "but thats not the same thing". I would say it is exactly the same thing. What these guys are telling you is Rusty's simply doesn't put the needed effort into ensuring each and all of their parts are properly put together and meet a HIGH standard of quality control. How do they know this, most all of them have seen at least one failure. What this in turn means is the uneducated folks whom don't research what they are buying, fail to take advice, or simply know nothing about how components come together will continue to buy their products because its what they can afford to buy. Its capitalism at its best. Produce a product at a price folks are willing to pay and in turn for the price, accept the shortcomings of the product.
You stated you didn't expect to see good reviews of Rusty's products. I am positive there are some good reviews out there, and there are probably some knowledgable folks which have had good luck with them, the problem is there are a lot of folks who have not had good luck in many aspects from quality, to customer service, and there are some knowledgable folks in this category too.
The reason I have an XJ with no lift on it is that I refuse to give in and just buy an RC, Rusty's, or other lift I am positive I will have issues with just because there are people out there that have not had issues. I have read enough things about breakage and carnage to say. its not worth it to me. I will wait and purchase a clayton lift because there are tons of folks who have great things to say about clayton. Have they had failures, yes.... guaranteed. The difference is how that failure is addressed and corrected. The difference is acknowledging a failure or weak point and improving it.
I am not trying to belittle anyone, Rusty's included, and I hope everything you bought or will buy lasts forever with no issues no matter what brand, however if your part fails and it fails at the WRONG, WRONG time, you will then become part of the failures these guys just warned you about, hopefully without a horrible outcome to someone in the process.