Because it's cool.
Everyone builds their own website nowadays with fancy animations, smooth transitions, and all that savvy jazz. But this makes the web boring.
So why not go back to the good old days when everything was simple and ugly?
I might even argue that it's more attractive to have such a website, because it's different from the rest.
I don't know. I'm just a README file describing why my website is in HTML4. What else do you want from me?