Trying to simultaneously satisfy many customers in a market where there are multiple options, different ways to slice and dice the customer segments, different dimensions on which to optimize a product, different ways to reach customers, different systems to integrate with, it's just a whole different ballgame to building a specific solution for a specific customer.

And at somewhere like google for example, most of the PMs are former engineers and can see technical changes enabling new things. On top of that, at somewhere like Google engineers do meet with customers, frequently. There isn't some dividing line like you describe because all the business units are run by PMs or engineers. They are "business" in your terms.

It is what it is. Your observations and suggestions may well be true and sensible in the environment you are operating in.