The volatile categories of food and fuel are excluded from the indices simply because they do fluctuate rapidly and in both directions. They try to get the inflation figure from things that are more stable and rise and fall slowly so that trends may be deduced..............
If we look at gold (yes, I know it's just a commodity, with no magical powers whatsoever) we can see that a dollar today is worth approximately 1.4 cents from a century ago. Do we really need a 'basket of prices' to tell us what one fairly stable commodity tells us?
Yeah, gold bugs are supposed to be crazy, but Occam's Razor supports a pure gold standard in practical inflation indexing. On the other hand, Occam's Razor doesn't keep economists employed full-time by the government, so it must not make any economic sense... :)