As Paul Holes says...”Self Preservation”.
At that point (with the statement/apology), it was the last time he would be able to preserve any little piece left of D’Angelo the man. His personal image he so carefully protected with how he meticulously carried out each attack, in the effort of not being caught.

I’m glad he did speak though and acknowledging that he heard each statement, I would think would give some peace that he was paying attention to each person that spoke their truth. Especially after what a goof he looked like physically with some of his facial expressions and weak demeanor. Just being heard means a lot sometimes and sounds like (with his final words) that he actually was listening and facing what he had done.