Personally, I hate the whole "bike assembler" model. It rewards speed, not safety, quality, and reliability.

I have worked for shops that had the "fill the floor, and fast" mentality, where 30-45 minutes was the norm for a safe and rideable build. I have worked for shops where the expectation, even on basic mountain bikes, was a complete disassembly, repacking of bearings, detension/retension wheels, checking frame alignment, etc. You could usually do 2-3 bikes per day.

Bikes at the former shop, we usually had repairs stretching out the door. Not necessarily from slapping them together, but I'm sure it played a part.

Bikes at the latter shop, we would often not see again apart from a quick tune-up once the cables stretched.

Personally, I think there's a happy medium, but I was much happier working at the latter shop.

Pete