I'm with you about CSS. It seems the target market of this app is geared towards Web->iOS devs, but that seems like a smaller slice than something like "Bootstrap for iOS" should be made to do. Bootstrap is great because it makes web development so much easier through native uses. It doesn't add another language paradigm to make web development easier - it does it inherently.
1) If you're gonna' call it "Bootstrap for iOS", have the analogy end there. The site is way, way, way too much like Bootstrap already. Brand it better.
2) Good native code should be inherent! Nobody should have to learn CSS to make better iOS apps! A beginner should have a framework for her/him that allows something easy like [view fadeIn] and it work. Then, if they want a little more control something like [view fadeInOverTime:seconds]. Adding a shadow should be as easy as [view addShadow] or [view addShadowWithCornerRadius:radius]. Rounding corners is already extremely easy using QuartzCore, but let's make it even more intuitive for people. [view roundCorners] and then [view roundCornersWithRadius:radius]. The whole point is to make development exponentially easier for anybody to come in and start making useful, beautiful things.
I'm working on a class to include that does all of point #2 plus a ton more - and seeing this post will probably be the catalyst to releasing it this weekend. I have a huge plan in the works for making extremely easy to use UI elements as well, but I think open sourcing this in chunks, then releasing the whole thing as an example on how they all work together is gonna' be the route I go. So far, I've released one part of the project that makes choosing good colors to use in the app a breeze (https://github.com/bennyguitar/Colours-for-iOS). The next one will be for UI utilities like the fade in and shadow code mentioned above.