I've listened to the debate about this for ages, taking everything on faith. From what I've learned, you can't truly separate layout and HTML. The best you can do is make it so minor layout changes will require only changes to the CSS. Big layout changes always seem to require changes to the HTML. People cite ZenGarden as an example of major changes with just CSS, but their markup is full of more id's and classes than would be reasonable for an everyday site. And people spend a long time tweaking to get stuff to work across browsers.

So I completely agree that using this (and most other CSS frameworks) is going backwards a bit in mixing layout with HTML. But I actually always did that. I just wish writers on the subject would help me not be confused by starting out by admitting that they are not following the notion of layout done in CSS.

Some people posted on here that Bootstrap is just for getting quick prototypes done, and then when things are stabilized, you should switch over to semantic, properly separated CSS. But if so, is that the intentions for all grid based CSS frameworks?