I'm playing devil's advocate here, but a full-time front-end designer might care deeply about such things. I would not, for example, take a J2EE job even though I know Java because I know they are not "just the same." I could see a designer caring about the stylesheets they'd be working with even though it's all fundamentally CSS.

Look, "text/less" is not something browsers understand. This question is also asking about the adoption of standards — this has absolutely nothing to do about stylesheets. Three aspects of the codebase are involved here: HTML (the lingua franca of the Web), CSS, and LESS.

Look at what the question contains: "presentational CSS classes in the markup". That's Separation of Concerns, not "stylesheets."

You're begging the question. And it's one question that can easily be generalized as a format-question: look at the operative words "use" and "utilize". Look at where they appear in the sentence.