What's wrong with an insincere apology?

My cousin found out her co-worker's long apology was insincere. That whole speech and ''heartfelt apology'' was fake.

She's more upset and now considers that woman a nasty person. She feels more insulted than the original offense. Why?

What's wrong with an insincere apology? At least they're trying to keep the peace. At least it's better than nothing.

Updates
+1 y
My cousin even said it would've been better if that woman never apologized if nothing she said in that long speech was true.
What's wrong with an insincere apology?
Post Opinion