Linux

There are two concepts in UI design that often pull in opposite directions. They are usability (the ability to do advanced stuff easily) and discoverability (the ability to find unfamiliar functions in the interface without resorting to the manual/the Internet).

Command lines are highly usable, but they're not very discoverable. Most people have been trained to want the reverse—discoverable, but often not very usable—and so the command line scares them. It's less a logical reaction than an emotional one, although not wanting to waste time on something they feel they shouldn't have to deal with does figure in.

Thing is, Windows' "everything is in the GUI" is an illusion. If you have to fix ailing Windows machines, or even just make one produce anything other than the default telemetry-infested user experience, sooner or later you're going to end up mucking around on the command line or in arcane undiscoverable interfaces that are an order of magnitude worse than anything Linux has ever produced. Give me a command line over regedit any day. But most people outsource the repairs to their ailing Windows machines so that they don't have to touch this stuff themselves. For Average Joe, finding someone who will fix his ailing Linux box for him is more difficult, because they don't set up counters in the big-box stores that most people buy their computers from.