Not weird at all if you think about how they're made. You see, the processor chips are baked as a large round disc containing hundreds of processors. Although the chips are identical by design, the ones in the middle usually are of better quality and can be clocked higher. However, the manufacturing cost is the same for each of the chips on the disk so if the baking succeeds so that they get more "higher quality" chips than planned, they of course try to get rid of them for a reasonable price.
There's also been cases where the highest demand was for lower priced slower yet fast enough processors which led the manufacturers to underclock their high end chips to supply that demand. When the overclockers found that out, the demand for certain models skyrocketed. AFAIK AMD did that with their Athlons to release more Durons in the early 2000's, don't know if that has happened since in a larger scale.