We don't try and "do" genealogy accurately because it is a game to see who is the most accurate and to see who can "judge" another's work. We try our best to be as accurate as we can be in order to reach the most accurate picture of our ancestors as possible. Often as we learn new information our picture of our ancestor changes--at least slightly. When we do shoddy work and research by grabbing whatever we can without analyzing it, we can indicate great-great-grandpa had wives he did not have, lived in places he did not live, and lived a lifestyle he never would have lived.
Sure, it takes longer to be as accurate as we can be. And all of us will make mistakes--beginners and experienced researchers alike. But do you want your descendant to merge your life with that of your cousin of the same name whom you cannot stand? Do you want your descendant to create a picture of you that is completely and totally inaccurate?
Our ancestors deserve that option as well.