Could this not be said about any stylistic choice though? Why should websites pick their own heading weight? What's wrong with the default text colour? Who are you to tell the browser not to use the default padding?
People have been mucking about with typography since Gutenberg's day and they're not going to stop now.
I'm personally 'font blind', but I don't have a problem with people being creative and making aesthetic choices.
While I'm totally on board with you on the principle that a website should inform the browser what is, not how to show it, that particular site is hardly the place for this discussion...
_ANY_ article about CSS and client side javascript however.. go go go! :)