Still has all the same failings in terms of mindset; declaring in the markup what you want things to look like for screen media... ignoring that HTML is about MORE than what it looks like for sighted screen users.
Thus saying things like "button-small" or "pure-u-1-3" is nothing more than dragging development practices back to the worst of browser-wars era HTML 3.2 and the vendor proprietary crap caused by Microshaft and Nyetscape's little pissing contest.
As I'm always saying if you don't know what's wrong with classes like that, PLEASE, for the love of Christmas admit defeat and go back to using HTML 3.2 with all those FONT/CENTER tags, ALIGN / BCCOLOR / COLOR / SIZE / BORDER attributes, and tables for layout you all so clearly and dearly miss.
And that's BEFORE we talk about pissing all over the markup with classes for ZERO legitimate reason other than incompetence. It's as bad as when people abuse the aria role nonsense becuase they didn't read the fine print. Really? A <button> is a button? Wow, never would have guessed...
Your HTML -- ALL OF IT -- whenever possible should say what things are -- semantically, grammatically, and structurally -- with zero concern for what you want things to look like. If you are choosing your tags or creating classes just for appearance, you have utterly failed to divine the purpose of HTML and why CSS is separate from it.
Hell, the way ALL these "frameworks" declare their own <link> clearly illustrates these clowns aren't qualified to write a single damned line of HTML or CSS. Do you know why? It's right there... where's the media="screen"? I'm SO sure their BS makes sense on print, speech/aural, TTY, etc, etc.
Big tip, if you see CSS that's only really for screen included without media="screen" or sent with the dumbass media="all", you're looking at the pesky 3i of web development. Ignorance, incompetence, and ineptitude. Goes hand in hand with all the other 3i the website for the project has, like illegible colour contrasts, thin-glyph fonts in excessively light weights, complete lack of logical heading orders making the document structure complete gibberish... and we're supposed to trust their way of building a website?!?
I mean lands sake look at their blog example! If you don't know what's wrong with their mis-use of numbered headings ALONE, you don't know enough HTML to even recognize how badly this type of nonsense is bamboozling you!
This is why these obtuse addle-minded frameworks end up making people write two to ten times the markup needed to do the job, whilst flipping the bird at usability, maintainability, and accessibility; calling into question the ability of those who CREATED this junk, much less the gullibility of those using them.
They are a blight upon the Internet, and at BEST are bunko preying upon apathy, ignorance, and wishful thinking. All they do is saddle people up and take them for a ride by filling their heads with information and techniques 23 years out of date, and preventing people from learning to use or embracing every advantage HTML and CSS are supposed to provide!