So does that mean using engineering and math as the basis of building bespoke software is not creative in that sense? Just curious, not criticism - because I always thought of designing the architecture of a large software system, making it work within constraints, codes, making it easy to work on, fit withing design constraints, a beautiful UI, even a new programming language as creative.

yes, exactly. Its an offensive term to say the least. Scientist are the ultimate "creatives" as they create fundamental things that all other fields depend on. But somehow they don't describe themselves as "creatives". Calling yourself a "creative" at best doesn't make any sense and at worst makes you look like a jerk.