not only is sugar certainly not terrible for you, it is the only fuel that your body understands.
you are not a hybrid vehicle. you take sugar. that's it.
so, virtually everything you eat is converted to glucose along the way. if you eat the glucose straight, your body just requires less energy in converting it. that is all.
that said, if you eat too much sugar then your body needs to find a way to store it, and that is where you get the various problems that are said to be associated with sugar, such as high cholesterol and diabetes.
but, the actual blunt reality is that these are actually not problems with sugar but problems with over-eating. it's really just a simple conservation of energy problem: if you don't eat too much, then your body won't store it the wrong way.
once again: the issue is not what you eat, but how much you eat. you are not what you eat. you are how much you eat.
so, don't worry too much about that errant can of pop or that odd bag of doritos. just watch the total intake.