Everything is a div
Div soup is what you write before you learn what the other hundred elements are for. The argument for fixing it isn't screenreaders or SEO, it's the next person who opens the file.
Web fonts and the flash of invisible text
Every browser has picked a different answer to what should happen while a web font downloads, and all of the answers are bad so the decision quietly falls to you whether you choose to make it or not.
float: left is a layout system
We are building every grid on the web out of a property invented to wrap text around a picture, and the pile of workarounds we've grown on top of it has stopped looking like workarounds.