Just to be clear and specific, formal engineering processes and corporate selling out are two orthogonal properties that should never be conflated. Stuff millions of people use shouldn't be slapped together as a "hobby" without careful testing and change control processes. It also should get sufficient (crowd)funding so it can get the attention it deserves.

I disagree, I would much rather see my OS made by hobbyists like myself with the same goals as myself rather than big tech who definitely don't have the same goals and values.

It's one of the reasons I use BSD on my main machine. I think Linux has been infiltrated by big tech way too much.

No one actually complained about Linux becoming more "professional" in terms of meeting high engineering standards. Just about corporate control over the process. There was a study that found code with more F-bombs in the comments were actually more professional according to the engineering standard, in response to complaints from suits that swearwords in the code meant that Linux couldn't be taken seriously as professional software.