The differences have little to do with skill, and a lot to do with resolve and intent.
The amateur contributes with unfiltered joy. There’s really no other upside–create your work because you can, because it helps someone else, because it makes you feel good.
The professional shows up even when she doesn’t feel like it. The professional understands the market, the customer and the price to be paid for work that’s worth paying for. But the professional isn’t a hack.
A hack is a professional who doesn’t care.
The hack has been beaten up enough times that he has emotionally disconnected. The hack has a short-term view, able to do what the client asks, without regard for how it will impact the culture or his long-term prospects.
Serviceable is for hacks. Memorable and remarkable belong to professionals and hard-working amateurs.