Because of the goals I've stated before.
I want to create a client which will push the networks development further, by allowing other developers to quickly experiment with new techniques and protocol extensions.
Of course, the clients source code needs to be well structured and easily extendable in order to allow this. I've found mutella to be especially hard to read and understand, mainly because of the complete lack of comments in the code, but also because you were using several not-so-common language cunstructs, many of which were completely new to me at that time.

If you...
a) convince me that mutella is suitable for the goals I've stated,
b) give me a detailled introduction to its working principles
and
c) promise me to extensively comment every bit of mutella source code you write in the future
I will gladly join you.

Guido