[a-priori]

I'm a developer who does take on side projects. I have two on the go right now, plus I'm the technical reviewer for an upcoming book. Yet, I agree with this entirely. I think it's silly to expect a "good" developer to code in their spare time, just like it would be silly to expect any other occupation to do so.

Instead, it should be like a carpenter that does their own home renovations, or an accountant who uses double-entry book-keeping for their personal finances: they're using their work skills in their personal lives. That's like a developer who makes up a tool to keep track of errands in their house, for example.

Or, it should be like a technical writer or copy writer who writes short stories in their spare time. That's like an application developer who writes games in their spare time.

In none of these cases would you think that an carpenter who hires professionals or an accountant who just does normal budgeting and so on or a writer who writes only at work must be bad at their jobs. Why should it be any different with programming?