The same people looking and working on the CSS are the same people looking and working on the HTML. HTML full of long complex class names is a bit harder to grok.
I actually prefer nice semantic HTML but I admit that's not always possible.
> HTML full of long complex class names is a bit harder to grok.
I wouldn't recommend long and complex names either, but with something like tachyons, they're not long or complex, there are simply long lists of orthogonal classes.
This helped me deliver maintainable and reliable stylesheets that other devs like.
Most importantly using only class names you will gain :
1. Your HTML / CSS is easier to maintain.
2. Is faster to develop.
3. Is faster to refactor.
4. Is more portable.
5. Is faster for the browser.
I even wrote a blog post about it [1].
http://www.drinchev.com/blog/css-with-only-class-names/