Soft skills are also teachable to a coachable person. I've seen it in action. However, far fewer people are receptive to coaching on soft skills because fewer people understand what "soft skills" are and why they matter.

I've met plenty of engineers (anecdotally, not a majority, but enough that it's a clear pattern, and strongly correlated with how junior they are) who lump soft skills into a single category represented by broad labels like "charisma" or "schmoozing" or "eloquence". But it's really a very big category of practicable skills.