Some people just don't like change. Whether it's change they don't like or just the look of the new Associated Content home page, I don't know. I personally think it looks a lot more professional and cleaned up which gives more emphasis to the purpose of AC for the general reader.
I only have two problems with it. There's no feature "Source" (the term AC gives us as writers). The topics are also just listed at the bottom. It would be better to have the topics more visible.
In any case, there's an uproar about it that I really don't understand. If it works, great! Why get upset?