I’ve had a car guy tell me the opposite-driving it before lubricants warm up is bad for cars.
You and the man who told you that are 100% correct. Any motor should get temperatures of the fluids within it close to the temperatures they are designed to work at before operation. For example it was 0 degrees this morning here and all fluids within the Jeep liberty had jelled....the oil/power steering/transmission fluid etc...let alone the need for the anti-freeze to heat in order to make the cab bearable....you are always better off warming any vehicle up.