Tube sound is not about warmth. It's about correct presentation.

a good tube amp design does not have to sound "warm" at all.  That is the old type of thinking based upon what you have heard in your experience.  BUT there are tube amps that are fast, dynamic, have great sonics that are not warm sounding.

Happy Listening.

Softer metallic sound is still the same metallic sound.

Modern tube amps and hybrids are the the my preference. 

Disagreed.

Also assuming tubes provide “warmth” then that’s a problem because warmth might be nice but it’s definitely not “correct”.

So the logic of the assertion proposed is flawed to start with and that kind of puts a damper on things right out of the gate.