"A professional always does everything necessary to complete a job. An amateur sometimes chooses only the fun parts."
My problem is, what is "a job"?
Most people work on a team in order to work on "the fun parts" and let someone else deal with the other parts. I'm lousy at marketing and sales. I cannot do graphical design. Don't trust me at all to handle the bookkeeping.
Those are all parts of of the job of releasing a software product. But I only find the programming-related parts to be fun.
That's why I'm a professional programmer, but not a professional in the other fields.
I also don't like this:
"An amateur golfer, for example, may thrill at the crack of hitting a 300-yard drive but hate putting. And so that amateur may frequently choose to pick up the ball once it's “close enough” to the hole."
Golfing has amateur championships. When Tiger Woods competed in the United States Amateur Championship in the mid-1990s, he did not "choose to pick up the ball". He did all of the parts, and did them well.
The USGAs rules about amateur status include things like a limit of $750 max prize money for the tournament. http://www.usga.org/content/usga/home-page/rules-hub/amateur... It's "amateur" because the golfers aren't making a living from golfing.