Speaking without thinking is something I can understand, but it's not an excuse. Nobody is an island, we're all standing on the shoulders of giants, and disparaging another's work when they're arguably helping improve your own project is an attitude I wouldn't expect in an OSS project. As someone else said, if this is the way the author felt about Tailwind, they could have chosen a proprietary license, or just left it without a license to fall back on regular copyright.
What happens a lot of the time is that authors choose open source licenses because they know that's how their project will attract attention. I'm not saying that's necessarily what happened in this case, but it's not uncommon to see authors of some OSS projects seemingly being surprised about how OSS works or what the mentality is expected to be in the project.