"Why are people defending the manufacturers?"
Because a few lemons are the exceptions, not the rule. Our Allegro has a few issues I grit my teeth about, like when the slide was in the sink drain line was kinked in half so bad it wouldn't drain, and finally split; or the drawer just last week that fell down in back because the stapled-on track came unstapled; or the mirror wall that I have to keep fixing-- The drain was a dumb mistake by whoever installed it. The other items I attribute more to bone-jarringly bad roads I have to drive the poor thing on.
Even the Space Shuttles came back with pieces that fell off. At least, those that didn't blow up on the way out.
Nothing is perfect. Not even a ridiculously overpriced Provost.
2000 40' Tiffin Allegro Bus \ 2003 Chaparral 260 SSI
1988 53 x 14 Skipperliner \ 1995 32' Party Cruiser
1984 Goldwing Aspencade \ 1976 Harley Sportster