Shuttleworth is rich and Ubuntu/Canonical is his personal feudal holding. They basically can do whatever dumb thing they want and none of it actually matters because they don't really need to respond to market forces.

I've worked for one of these businesses before - basically staffing a daycare running a very compelling roleplay scenario so a millionaire/billionaire has an excuse to get away from their family for 10 hours a day. It works best if you're a fresh grad college kid who doesn't realize any of that for a few years and is just glad to have gotten a job.

So, the actual intent of all of their hiring circus is to ensure they don't accidentally hire someone who realizes what's going on.