[gnicholas]

This is more likely to be true where you are selling to other technical people. But it becomes much less likely to be true when you are selling B2C, or to non-technical businesspeople. And of course, the ability of a technical person to learn sales varies quite a bit. Some technical folks pick it up easily, but others do not (or find important non-technical bits like fundraising and sales to be very distasteful/annoying).

[notahacker]

And of course the reverse is true. Some "business people" can pick up a huge amount about UX, client priorities, process automation and what is and isn't technically possible and make useful product management contributions even if they never touch the codebase, and some simply aren't interested in that level of implementation detail even if they're really good at selling the big picture and someone really needs to get a handle on that side of the business.