But they are hugely commercial in selling their crap and professional at that. The fact that they sell burgers, doesn't mean their burgers are of professional quality though. They can still be of high / low / bad quality.

Which has been my point all along. Doing something for a profession, doesn't mean the quality will be professional !

High quality and professional quality are two rather distinct things indeed and I never claimed otherwise.

Professional quality to me is where people go for the boundaries and potentially raise the bar higher.

Professional work can be anything from lifting a manhole cover to singing a song in front of a live audience. It still says nothing about the quality of said actions / professions.