Is beauty universal for user interfaces?

I am a sales person for a building automation company. Without getting into the weeds, we put small computers on heating and cooling equipment to allow them to run most efficiently. We also provide a user interface to allow the building operators to interact with the system.

I have mechanical type engineers build the graphics for the building operators interface. I sometimes question the beauty (let alone UX!) of their graphics implementation, and they say "each building operator is unique and wants their own look, and what we built is exactly what they wanted".

Do you feel beauty is "somewhat" universal for user interfaces, or totally unique for each viewer? If the former, how would you respond to someone who states the latter?