Wow, some people really have some disdain for that foam pad. At least they're doing squats, right? I think it's all a matter of preference. I know some guys who squat much more than I probably ever will and they use that pad. If you can stand using it, then why not? A heavy bar on the shoulders/lower neck will affect you over time.
Personally I like to have the bare bar on my shoulders, but as my weights keep going up I think about using that pad more and more.