Vulcans are arrogant, not racist. I'm sure serving on a ship full of ONLY Vulcans would just make things worse.
Frankly, I want to know who allowed a Starfleet ship to have an all-Vulcan crew. What possible purpose could that serve?
Physical comfort levels could have something to do with it. Andorians come from an ice world and Vulcans come from a desert climate. Adjusting common areas of the ship to accommodate both extremes would be nearly impossible.