I'm the handy type, or at least I like to think I am. I can swing a hammer reasonably well, I've so far avoided amputations while using jigsaws and the like, and I can usually come up with a solution which at least makes whatever I'm fixing work, even if it's not exactly pretty or perfectly functional. That's a useful skillset, but it does have its limitations.
I've no great objection to homeowners doing their own maintenance, but there's a caveat to that: so long as they don't endanger themselves or others. Far too often, one sees horrifying things like loose electrical cables, connected any old how, in the general vicinity of open junction boxes. It scares me; the colour codes of electrical wiring exist for a reason, and it's not just to look pretty. When doing electrical work, every wire is hot until proven otherwise, but there's a certain expectation. I'm not familiar with US standard colour codes, which is one of many reasons I will not do any electrical work over here, but I can't imagine they're any less strong than the British ones about having hot be distinctive in colour.
Similarly, I don't work with drywall, because finishing skills aren't that notable in my skillset. If I were working with it, though, I like to think I'd at least have the sense to read up on it first. Get a feel for fire safety requirements, what you really shouldn't do, and so on.
I enjoy exercising my problem-solving skills, but there's a time and a place to let the pros handle it. I probably know enough to do my own brakes, but I'm not confident in that ability; I won't bet my life, or the lives of others, on that. I'd far rather underestimate my own ability than overestimate it.