I think the biggest thing is documentation. Tachyons has basically none, the only way you would even know that you can do responsive design with it for example is by reading all of the CSS.

Case in point from this very thread:

> i'm trying to find it in the docs - but how do you apply a different border on mobile, tablet and desktop via tachyons?

https://news.ycombinator.com/item?id=25333465

You can't cross the chasm from early adopter tinkerer types to the more mainstream community without teaching people how to use your tool.