It's a weird world where kids are more scared of the metric system than they are of a credit card-sized Linux computer with its guts showing.

It probably is just a matter of being used to it. In the EU we are used to the metric system, but are ok with screen or hard disk sizes expressed in inches to the point if some brand advertising offered a 1.5 meter wide screen TV most of us would look for a calculator to make the conversion, including myself. If we changed to the metric system also for TV sizes, most people would find it uncomfortable at first, but probably would adapt in months.

In my experience, Xbox controllers are actually fairly common for large robotics. It is relatively cheap to buy a controller and USB wireless dongle plus there are lots of software libraries to help interpret controller input.

My main experience being my participation two years in a row in the Intelligent Ground Vehicle Competition (IGVC). A college competition to develop self-driving rovers and "cars" (golf carts). There were around 40 teams from various colleges (several international, not just usa) and many of the teams used xbox controllers for manual control including my team.