"All" is not true...IF you have $200k+ for a Tiffin Class A, you will get a real quality unit.
Sadly, most RV manufacturers pay their "Amish Craftsman" on a piece-meal wage, so the poor guy with the pneumatic screw gun doesn't pay his bills unless he gets x # of units out the door every day. When you're under the gun like that, quality is not your first priority.
Anybody else remember that guy Marty from the early days of the forum? He pulled his TT out onto the NJ pike and wheels came off, and he was trying to build a bandwagon here while he was suing Tom Schaffer RV and the RV manufacturer for not tightening the lug nuts? Consensus here was that the guy was such a nut that his neighbors probably loosened the lugs for him....