I don't understand this claim.

Building something people want is marketing? Requirements gathering? Business analysis? Project management? Engineering? These are just subdivisions of marketing?

Yes, actually. Academically marketing is defined by the general marketing mix of: Product, Pricing, Place, and Promotion. Product here relates to fully understanding the end users goals. You then need to design a product that meets those goals, and a brand which communicates to your user how those goals are met.

It's common place now for people to think of 'marketing' as 'advertising'. It is a much more robust subject than that. This is driven largely by the product management role being so closely integrated to the engineering flow. As I understand it, traditionally product management was a marketing department role. You can see this more with non-software companies like food or transportation.

Interesting TIL. Definitely not how I perceive marketing though. I always saw it encompassing promotion and brand.

> I don't understand this claim.

I'd say it is more accurate to characterize your points as a "marketing feasibility analysis". But this is as much my opinion based on my understanding of marketing, as it is actual "marketing of a product" per se.