Thousands of years ago, when our species was still evolving, obsessive and persistent acquisition of the very best weaponry (spears, clubs, arrows, etc.) was a trait that had tremendous survival value. For example, with a slightly improved spear, you could overwhelm an otherwise vastly superior foe, armed with the old, non-dimpled spear. So this trait was honed and bred into us through natural selection. Thus, in modern-day sport (i.e. sublimated warfare), it's only natural for us to hew to this strongly imprinted trait.
-jens