The building and the tent is the wrong comparison. The right comparison is between a well setup assembly line (say at some other automaker) and one tossed together in a parking lot.
FTA: "The chaos of how Musk is going about this makes it difficult for him to provide the standardized, repeatable work routines that allow people to function"
It's not so much the tent that's the issue. It's more to do with the "fk it, we're in a bind, quick, everyone in the tent" approach which is raising eyebrows. Say what you want about Tesla, but they do make for interesting watching. I'll be grabbing my popcorn for this new episode in the story :)
Sure they're not putting together internal combustion engines but still, tolerances are important and can vary quite a bit without temperature control.
I'm no pro but I've worked in a few auto assembly lines.
They are constantly reworked and the only real support they get from above is lighting and HVAC. Stamping isn't going to get moved very easily, but most other processes are pretty much bolted to the floor. As long as you have power and reasonable environmental control I don't see why it wouldn't work. It's ghetto but whatever.
The “tent” probably will result in a better quality production line since it is a single arch structure with no internal support pillars restricting access or positioning.
The “tent” also likely has better quality air due to not using 40 year old air handling plant.
The mischaracterisiation of the new building as a tent is indicative of the lack of actual concerns about the new line, meaning the short propagandists have to invent new fears.