They probably have been using it for years, and for the last more then a decade I've been using Ubuntu as my main Linux distribution since I have work to do and I'll get to doing work faster in ubuntu than any other distribution.

Why did I start with Ubuntu? 10+ years ago Ubuntu was lightyears ahead for community support for issues. Again, I had work to do, I wasn't hobbyist playing "fuck windows".

In fact look at things like ROS where you can get going with "apt install ros-noetic-desktop" and now you can build your robotics stuff instantly. Every dependency to start and all the other tooling is there too. Sure a bunch of people would now say "use nix" but my autonomous robotics project doesn't care I am trying to get lidar, camera, motors, and SLAM algorithms to work. I don't want to care or think about compiling ROS for some arch distribution.

I won't say I don't dabble with other distributions but if I've got work to do, I'm going to use the tools I already know better than the back of my hand. And at the time, when selecting these tools, Ubuntu had it answered and is stable enough to have been unchanging for basically a decade.

Oh and if I needed to, I could pay and get support so the CEO can hear that risk is gone too (despite almost every other vendor we pay never actually resolving a issue before we find and fix it.. Though I do like also being able to say "we have raised a ticket with vendor x and am waiting on a reply").