Read the article the whole article.

The author was the interviewer, and the comment came from a candidate that wanted to research his interviewer as preparation for the interview.

The reasoning why he thinks one should have a personal website follows in the paragraphs "Practice" and "Learning".

>the comment came from a candidate that wanted to research his interviewer as preparation for the interview

That's weird as well, I would never research the interviewer (as well as I never got to know the interviewer prior the interview) but instead abouth the company, business, technologies and things like that.

About practice and learning you don't have to have a website, there are many ways to keep your memories and skills up to date.

Because others will. It's an arms race.

You may want to know: an arms race in what war?

Put another way:

- Who thinks it's a meritorious thing that someone screws around on Facebook, twitter, or personal blogs all the time? - Who specially wants to work for/with the people who do?

Not that it's a bad thing. But why is it a good thing? And why should we think the people who do think it is a good thing are significant?

The war of getting hired in the tumultuous tech industry. Others will sell their brand online, so you will do it yourself, or you will be outcompeted. I don't think it's inherently good to do it, just necessary.

Thousands of years ago your ancestors may have asked why they should adapt their teeth to be able to survive on either meat or plants. And it would have been a good question. Nevertheless...