And if you buy the Hackers & Painters analogy, you'll see programming, marketing, bizdev, etc as arts.

It can be hard to observe improvement in these areas; however in the link it's very easy to track the author's improvement.

It's a quite visceral manifestation of improvement - you see the results of daily practice at a glance. It's a reminder to practice, to be better.

"Because n people voted it so.

'On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups.'"