I always hear people talking about their drop aways rests. What exactly is the point? I hear its so your fletchings don't contact, but cant you just line up your nock so they don't touch? Please inform me because I will be buying a new bow and accessories this spring and would like to look into these types of rests.

It isn't just so that the fletching doesn't touch the rest, after you release no part of the arrow touches the rest. There is little to no contact between the arrow and the rest upon release.

Like Washington said, the rest looses contact from the arrow after about three inches of travel. This reduces any ill effects from you torquing the bow since the rest isn't able to move the arrow around before it leaves the string.

For fletching contact it is true that you can align your vanes or feathers to pass through the prongs of the rest but you are very limited in how much offset of helical you can put into your fletching and still have no fletching contact. Many people like to use hard 11 degree helical and that will not pass through a TM style rest with out contacting the prongs.

IMO there is no reason not to use a drop away except if you use a biscuit type rest.