Oh, fully agreed! And I think Pirsig would have agreed, too.
Regardless, you need some level of understanding to make the call. A particularly funny anecdote from the book, if you read it, is when he decides some fix is too delicate for him and takes his motorcycle to a repair shop. Right from the start he gets a bad vibe -- the mechanics are all kids listening to loud music and seemingly not paying attention to what they are doing. This is later confirmed: they return his bike without fixing the problem, then try to fix it more seriously but forget to screw some vital parts, leading to additional damage, and in the end they completely fail to fix the problem. What's important is that right from the start Pirsig got the feeling something was off about this repair shop, and he could sense this because he know enough about the components of his bike (for example, he guessed they had forgotten to screw something down simply because it's easy to miss and he knew this screw was there).
If, like his friend John, you decide "I have something else to spend my time on, better leave this to the professionals", it might seem superficially a pragmatic choice but it could also make you fail to notice the repairmen who are bad at their jobs, until it's too late and your piece of machinery fails catastrophically.