take it like this, Intel targets consumers that usually buy PC by bulk (office, lab, school) that won't usually overclock their PC. this is why their architecture are not that overclocking friendly, and build to have the most MHz. While AMD too caters to these category, they build the architecture so that it don't need a proc that has a fast speed, but still can be as fast as their intel counterpart.
But that was long ago. Now Intel has changed that you cannot say overclockers prefer just AMD anymore