The purpose of the strategic reserve is to act as a buffer in case of supply shortages.
Given the extent of US dependence on oil, having such a buffer seems like a very prudent thing. I guess I don't see a reason to sell, unless it's because the government shouldn't be involved in such things, in which case, yes, I buy that part. I guess I could see privatizing the strategic reserve in some way, although I'm not sure exactly how.
BTW, did you know that the once-extant US grain reserves were sold some time ago? The country now has no food in storage to help in the event of a disruption of supply due to transportation, harvest, disease, etc.