Large Slices (10%)

A large pizza (18-20") should be sliced into 8 slices max.  What's up with these places that cut their pizzas into 10 or 12 slices, or maybe even more? 

A medium pie should be sliced into 6 slices max.

I really can't figure out why this is so important, but I really belive the pizza tastes better when it's cut into big slices.  When I try to think rationally about this, I know that the proportions are the same no matter how many slices, but still, when you have big slices, it seems to be cheesier or something.  I don't know why this is important, but I know this is important.