There's valid points here, but the impact is lost in the disjoint laundry list communication style.
Amateur means something more like "doesn't get paid". Professional means "gets paid."
Consider amateur marathoners. Some indeed "stop when they achieve" their first marathon. Others dedicate years to participating in marathons, and running culture. But they are all amateurs.
Some amateur marathoners "have a goal" - do a marathon. Some "have a process."
Most amateurs runners do not "think they are good at everything".
Many amateur runners have coaches, and join running clubs, and read advice books, all to get feedback and coaching.
Go down the list, and pretty none of it applies to dedicated amateur marathon runners.
Nor does it apply to other fields, like dedicated amateur birdwatching.
Professionalism to me means a few things: - you earn money with the thing you do - given a outline of the project you can judge how long it will take - you also care about communicating your work - once you agree to do something, you do it unless you can’t