The other reason Lab ships might look like that

[CordwainerFish]

I'm trying to recall what the gravity was supposed to be inside the main module. According to what I can find, the portion of the ship with the carousel is about 12m in diameter, and was supposed to rotate at 5 RPM

Which comes to about 1/6 g.

 

[phavoc]

Which comes to about 1/6 g.

Thats not optimal, but helpful for longer voyages.

The RPM would still be a problem, but possibly treatable with drugs. I dont know enough about the biology or pharmacology to know if you could treat it on a semi-permanent basis without causing other problems.

And im sure there would be those who dont respond well at all, like people who are sea sick no matter what they take. I went on a deep sea fishing trip with big swells, took my dramamine but still got sick. There were these old bastards on the back deck having a grand ol time as the wind blew the diesel fumes back on them. None of the were affected teddy while I fed the fish my breakfast a few times.

 

[Condottiere]

Outside of spacestations, it might be a concept that has to be let go for spacecraft.