It was ridiculous, but back for Min 1.0 and 1.5 I couldn't fit in the extra ten or so bytes gzipped and minified. Back then, Min's priorities were "fit in as much stuff in 995 bytes and support IE5.5 as an intellectual exercise".

They have since shifted to "make a CSS framework that can actually be used by other people, while still staying under 995 bytes". I also got another person (Scott O'Hara, https://github.com/scottaohara) to contribute; he made several useful contributions and also made size optimizations. As a result, Min 2.0 will be 995 bytes and also include a (clearly superior) 12-column grid. It will also include many other useful features, like a better responsive navbar and better icons, include all of Bootstrap's features, and it will still support IE5.5+.