Dick Lipton and Ken Regan, for example: https://rjlipton.wordpress.com/

Scott Aaronson: https://www.scottaaronson.com/blog/

Jeremy Kun: https://jeremykun.com/

Also, although he's a mathematician rather than a computer scientist, there is Terry Tao: https://terrytao.wordpress.com/

Busy people are busy, and choosing a 'better' platform or rolling your own site would be a monumental waste of their time.

I don't see any sense in attacking the credibility by the choice of the blogging infrastructure - the author wanted to convey a message, present his findings and he achieved that. This should be the only thing that counts.

I guess the best (even if in a totally opposite field) argument against opinionated choice of web-technologies would be the website of Berkshire Hathaway [1]. They invest in highly sophisticated companies but still use the website that always provided the service they demanded.

[1] http://www.berkshirehathaway.com

Dan Luu doesn't even use a blog engine. https://danluu.com/

If you do get one at some time, and find you enjoy Wordpress, I warmly recommend WP Engine.