OnkelC is German, if I'm not mistaken, and "friable" is a common word in the French vocabulary. German and French share a few cultural bias that may transpire in our English vocabulary. Also, "bröckelig" seems much less English-friendly.
Couldn't have put it better. I was looking for an english translation to the term "mürbe", took the first translation out of http://www.dict.cc/deutsch-englisch/mürbe.html