Fitts’s law

Here's a great old Kevin Hale article that has been posted over the years but never got discussed: https://news.ycombinator.com/item?id=62829.

I invited Kevin to repost it. If he does, we'll merge this discussion there.

Edit: comments moved to https://news.ycombinator.com/item?id=16613903.

If someone can tell me how to convince 20-something developers that this law matters, I'd like to learn. "Why are your fonts so BIG?".