TP is talking about the use of classes as mixins. One class could style the container and another could style the contents. I use multiple classes to add effects like hove via JavaScript. Hover can be a single CSS description rather than dozens of alternatives such as box and boxhover.

I'm talking about NOT using presentation-specific such as "box" or "blue".

Having class names such as "two-columns blue hoverable" are slightly more convenient but strategically similar to in-line styles.

Keep that presentation/behavior shit out of my content please.

Modularity is not a difficult problem to solve. But overloading your HTML is damned near impossible to dig yourself out of.