Not sure who says that, but I’ve never seen anything further from the truth. Those are two separate skills, not in any way related to each other. One can build, another can sell. Those are not necessarily the same person. Matter of fact, from my experience those aren’t the same people and for that exact reason companies have sales and engineers. Are there exclusions from this rule? Of course. The fact still stands - product builders and product sellers - two kinds of folks, which when working together have a better chance of succeeding.
My 2c? Everyone needs to do what they are good at and let other professionals handle their side of things.
you are 100% right both are different domains.
But some people think selling automations would make more money so, They just start to build an automation and think selling it would be easy because of the hype and demand for it.