The problem people have with nudity stems from religion. The main example most will relate to is the "Adam & Eve" story. Practically God says "nudity is bad". So religion has once again influenced society in a negative way (big surprise there).
Nudity is not bad, we (as a society) have a negative view thrashed upon it. We should love our bodies and never be ashamed of them. Everyone is beautiful, its just that we as individuals have prefferences and the accumulation of those preferences make up a majority, or society's viewpoint. Its unfortunate that this majority is so obscured and faulty, with too much emphasis on outer "beauty".
Seeing others naked bothers some because they were brought up to think its wrong to see the "privates" of others. Honestly it wouldn't bother me whether the world goes around nude or clothed, because it really doesn't matter.
Being naked is a freeing experience. Not bound or discomforted by the confines of our clothing. Clothing does have practical purposes of course. Keep us warm and, at times, safe. Also there is an eroticism that comes with the removal of clothing (or the teasing wiht), to finally be able to see your lover in all of her/his glory.
I have come to find that some of the happiest moments are when your able to be nude. for example: i'm currently in a relationship and the most wonderul place in my mind that i could be is snuggled in bed with the one i love, completely nude.
Maybe the human race was never meant to be clothed, as much as we are at least. There certianly is too much of a negative light on nudity. If nudity was more accepted, there would be a lot less "taboos".
Also, You certianly don't emerge from the womb with a cardigan on do ya!
Birthday Suit Up!