Interesting article. What is your position? You should post your opinion.
You first! Seriously, though, I think the situation depends on the project. In a business setting, there are contraints like timeline, budget and approvals that will tend to define completion. But on a truly creative project, it's a completely different matter. I suspect it may have more to do with personality – is the artist a perfectionist? If so, he might toy with an idea over and over, on and on, and never feel that it is done. Personally, I tend to have so many ideas that I'm ready to blaze on to the next one before even I feel like the first one is complete. One's mileage varies.