Adam Wathan actually wrote about it:

https://adamwathan.me/tailwindcss-from-side-project-byproduc...

I think one of the most powerful things was making a course then giving it away - really goes far to boost your prominence as a developer and building those lists.

They wrote a book that is pretty popular. Thanks to their connections with the Laravel leadership they got Tailwind as a somehow default for the front-end in Laravel. I dont know if it is organic or not, but there are dozens of articles about Tailwind coming up daily in sites like Medium and Dev.to.

Have you seen the trailer for Tailwind 2?

https://youtu.be/3u_vIdnJYLc