Several years ago, I rolled a piece of vinyl out in a kitchen. At the end where it went into the utility room, the outside wall ran out 3 inches in 6 feet. When I asked the contractor about it, he said the foundation was poured crooked, so he built the house to fit it.
Same guy, in a million $ house. Stairs leaned sideways, cabinets fit on both ends of a wall but there was a 2" gap in the middle, all of the door openings were different sizes (none standard), he curved the sheetrock to the shower stall, when it got hot outside, all of the vinyl siding swelled up and fell off.
Oh he finished the roof of a house and left off the dormer. And I saw other jobs that were worse.