I disagree. Your response to using ">" for tight layering of selectors is valid but I'm not advocating that here. Using loose comginations is fine. For example, if you want h2 to be different in main, header, footer, aside no matter how far they are nested ithen

header h2 {color:red;}

main h2 {color:blue;}

is valid and doesn't require classes. My main complaint about classes is that it forces them to be used in html. If you want to render the same text with a different css, you have to keep track of what classes are in the html. If you primarily style tags, then you are good to go.