That's a little bit like saying a barber should only cut hair the way he'd want to wear it. Being part of a professional, maybe the defining feature is to be able to understand what customers want and to do it without bringing personal preference into it, unless that's asked for.
I don't think professional designers have the option of only designing for themselves.
It's a bit like only programming for one's own problems. Sure, some people can do that, but most need to solve other people's problems to pay their bills.
I like your sentiment, but I think this only works at the start. After the initial MVC phase, you discover additional potential target audiences, and often (but not always) it makes more sense to apply empathy and adapt the software to also benefit their needs, rather than just abandoning then as "not the intended audience".
When your needs aren’t in alignment with your user’s needs then you’re the wrong person for the job anyway.
User feedback is important for getting additional insights, but the implementation of the feedback should always feel correct to you too.