There's too much fluff in that description. If i were a potential user and saw that line, i would just close the tab without trying to understand what you're trying to say. The op rightly described the essence of what makes bootstrap compelling imo.
Not being able to understand something doesn't make it "fluff". I believe that there is actual meaning to what I wrote (maybe you disagree, and that's okay... but it would be nice to hear what exactly you think is "fluffy" about my explanation).
As opposed to the original explanation, yours actually applies to virtually any CSS framework, so makes no argument after all.