Adam acted as a representative of the human race. Since we are all created as free, moral agents, perhaps we would all eventually have done the same as Adam did anyway. It depends on whether you are looking at it from God's standpoint or man's. God can find no good in man that would help to earn him a place in heaven. As far as righteousness or fitness for heaven is concerned, God says there is none.
Man is totally depraved.
It means that sin has affected every part of man's being, and that although he might not have committed every sin, he is capable of doing so. God sees not only what a person has done but what he is in himself. What a man is, is a lot worse than anything he has ever done. They separate man from God. Undoubtedly they are, but we must not compare ourselves with others.