That is true, but if the website is meant to be used as a resource then it should be designed to be easy to use and implement instead of having to look at the website's actual source html to get a feature working
Wow, someguy. You're right. Fuck them for creating and giving away free _CSS_ animations because you don't like how they are packaged. Webdevs shouldn't be expected to apply CSS classes to things without handholding. /s
They were giving pretty reasonable and, I dare say, obvious feedback. The site should provide an HTML snippet like just about every other demo page out there.
I can't see the author disagreeing with that.
You could copy and paste your "fuck them, right? /s" snark on just about every bit of feedback everywhere. I don't think that's very constructive, and it demonstrates a misreading of the parent comment.
You don't even need to inspect the elements. The code is available right there on the page by clicking the third circular icon at the top-right (the hover text says "Generate code").
Clicking on the icon `{.}` will slide out a div that contains the code for the CSS animation.