Right now, every RV manufacturer is selling every RV they make and cannot keep up with demand. Thus, there is no incentive to instigate any real level of QC.
Rather than spend time/money on rigorous QC, the manufacturers rely on customers doing the QC in terms of finding the problem, which they then claim they will fix under warranty.
But, as many posters know, buyers are often hundreds of miles from their selling dealer and either rely on a local dealer making warranty repairs (though many (most?) dealers who did not sell an RV are reluctant to do warranty service) or, as others in this thread have said, owners would rather make repairs themselves whenever possible because they don't simply want the problem to be fixed back to its original condition because it was lousy design/build in the first place!
Using this strategy, the manufacturer saves big bucks in terms of factory time doing QC, and/or making repairs under warranty.
The situation will not change until some kind of federal regulation is put into place a la automobile industry, or, as one poster suggested, one RV manufacturer takes the moral responsibility of building a truly quality product at a competitive price. Buyers would flock to that product!, and, after all, it only takes a little more effort to do the job right the first time.
In the meantime, it's best to hone your carpentry, electrical, plumbing, and mechanical skills. I have learned more than I ever thought I wanted to know about RV's in the last five years, and have decided it's all just part of the great adventure we call camping!
Happy Trails!, and