Sometimes processors are actually 'under-spec'd', so overclocking can be like.. reclaiming the loss. It seems to be a cheap way for AMD or Intel to offer a line of processors that range from 'value' to 'premium'.
As for the components wearing faster, true if there is a lot of heat, but that's why you have pure copper heatsinks and 120mm fans
Can't dan just config his system the way he wants?