Lack of detail, eh? Let me tell you something:
CCBS was actually designed to have a lack of detail in the first place. The reason of said mention is because there are objects called "details".
Simply put, details add detail; you clip them onto a CCBS she'll whenever needed. However, the Shell itself adds lots of detail just by existing. How, you might ask?
Simply put, CCBS was designed only to have non-versatile shells and bones to connect together and make something easy-to-build. CCBS was only made to be versatile and undetailed.
Now, granted, there are certain parts (like the Breakout and BA torsos) that have miniscule detail. However, you can't make much out of these parts as versatile. You could build a house out of CCBS, but with normal mechanical technic Bionicle, you have no ability to make anything outside of figurines.
Granted, CCBS is used to make figures only, but can achieve so much more than Bionicle parts can with organic creatures.