I read the article after reading a few book chapters and I have to agree with the criticisms about the support files and downloads. But thats easily rectifiable by someone at OReilly I would have thought...

I also agreew ith the comment about deep directory structures. This is something I had a lot of probs with early in in moz hacking. So much so that it took me four attempts before I stored up enough patience to persist with it.

The author does go on though to praise Mozilla and the platform though, so I reckon its a balanced article.