ysvry, the blender evangelist ;)

I've never written any code for blender, but it wouldn't surprise me if the code base were a bit of a mess.  Then again, it woudn't surprise me if the same were true for Max or Maya: it's something that happens to programs that have been around a while, particularly when they've changed hands.  I've wanted to recode things I've been working on from scratch because of the mess, but with something very feature heavy it frequently isn't worth it because the next release will be missing features, something that isn't acceptable to your end-users most of the time, especially if it's a commercial product.  Actually, I think they have done a bit of that with Blender in the past few years, I remember a few things when I first picked it up being very limited with promises that they'd be back soon and better than ever---and they are!