Most people don't communicate well, and by extension most people don't apologize well.

A bad apology, a selfish apology, downplays the impact and throws out excuses, in an attempt to make the apologizer feel better. However, if you hurt me, you don't get to dictate how it affected me, and I don't really care about why it happened.

A good apology, a generous one, understands or explores the impact and moves to mitigate it going forward. It takes more, and it gives more.