yes, listen to evan. he will tell you that you are wrong to carry one, and there is no possible reason to do so.
oh wait, one reason might be that a longer sleeping pad might be packed into a tube shape in your pack withe everything else packed down inside, therefore not too fun to remove (and repack your whole pack) when you want to take a five minute break. another reason might be not wanting to get your sleeping pad muddy, dirty, covered in pine sap, etc. also, if it's only 1 oz, perhaps that really doesn't matter much, or is multipurpose as padding for a pack back. i am sure there are other reasons too. i don't use one, but i see little value to telling people that there is NO REASON to bring one and WHY ON EARTH would you do that, etc.