I think I'm still a fan of Adam Wathan. It seems like it would have been so easy for him to credit Windi CSS, and it would have made it an all around great video to me. I don't understand why he didn't do it. Perhaps if I had done it I would have talked about Windi CSS for five minutes and it would have distracted from the point of the video. Maybe even talking about it for five seconds would have distracted from the point of the video?
FAAMG companies also don't credit people for making bits and pieces of things they release, even when they directly use them to deliver a key feature. In this case he didn't use WindiCSS' code at all, and it seems like they probably wouldn't have needed to because they no doubt took a different approach. Maybe Adam Wathan is a bit like Steve Jobs.