[praptak]

"First, "professional" and "amateur" should be defined to better make his point."

I think that the whole article is the definition, if not explicit than at least inferred from the examples. Not that I think that the only proper definition of 'professional' is: boring, limited, uninspiring (the author seems to suggest that).

On the contrary - there are some things that discern professional software development from unorganized mess and I'd rather have them in place: source control, automatic and repeatable build and deployment, regression tests etc.