It could be, if "part-time job" simply meant an ordinary job which one works for fewer than ~2000 hours per year; but "part-time" also means "no benefits", "no stability", and "no respect", and in any case there are no part-time jobs to be had as a software developer. If there were, I don't imagine they'd be much good for making a living.

What I want is more about flexibility than about a smaller number of hours. I'm happy to work 50+ hours in a week when it's called for; I just wish I could take a month off to go travel, when that's what I want to do, or take Thursdays and Fridays off for two months because there's some project I want to work on, or take a week full of half days because we just shipped a release and I feel like goofing off a bit. I mean, sure, I could probably just do the last one, unofficially, but I'd like it if this were all above board and OK, instead of just something you try to get away with and hope nobody complains. And there's just no solving the problem of wanting to travel: only once in my career have I gotten a month off, after almost seven years at a single company, a tenure I will probably never repeat. Why is PTO always non-negotiable? I don't get it.