Why is that uncomfortable? I don't think anybody takes issue with the idea that some engineers are great at being engineers but not great at being managers, and

Why is that uncomfortable? I don't think anybody takes issue with the idea that some engineers are great at being engineers but not great at being managers, and so it's important to have a career track for senior engineers to continue doing the engineering work that they're great at instead of forcing them into a role that's not fulfilling. That idea shouldn't be more uncomfortable just because the engineer is a founder. It should be reasonable for a founding engineer to let somebody else come in and do the boring management work that a CEO has to perform while the engineer continues doing the work that got them to where they are.