I think it's more so that people don't have the time for a productive garden. There are certain times of the year that my small garden becomes the workload equivalent to a part time job.
With composting, weeding, killing squash bugs, seeding, planting, harvesting, and pickling..... I can see why people opt to do something less time consuming.
Man, guy behind us has a beautiful garden. Just a little plot, probably a quarter acre, but it looks so much nicer than the plots on either side. More functional, too.
It's the other way around for me, I don't know anything about pruning.. one of my neighbors cross over to my side to have a chat, and asks, "new home owner, huh?"... I instantly laughed and admitted that owning a home is a HUGE learning curve. You either learn how to maintain your property inside and out, or you pay out the ass to have someone else maintain it. No other option, unless you want to be that neighbor that everyone hates.