I think this shows the amount of bloat in an Open Source package increases with how widely used the project becomes. As an article posted a couple days ago on HN pointed out about 75% of Linux development is done by corporations these days. Those corporations often times create the same "good enough" code that most proprietary developers do.
Now the theory behind Open Source is that developers around the world can see bloat and fix it. But with very few exceptions the corporate developers aren't going to make their code more efficient. So you have 75% of developers creating bloated code and at best 25% left to fix it.
Meaning the amount of bloated code easily overwhelms those volunteers who are willing and able to fix it.