Yes, often times that can be sufficient. If you just want to study the protocol or build a custom client. Often times one would like to modify messages of the protocol in order to find flaws in either the server or the client and the ability to man-in-the-middle the protocol makes that easier, in my opinion.

For completeness, the whitepaper is here: http://matasano.com/research/bypassing_openssl_pinning.pdf

Awesome article and white paper.

(Modifying the binary is much more fun to blog about, though.)

jerematasno thanks for mentioning cycript. I didn't know about it. Just watched Saurik's intro video. Very fascinating.