Because there's another mass shooting every couple days. It's hard to care about why one dude did something crazy 7 years ago while bullets are still flying. People are much more focused on trying to stop the next one.

That's daddy long neck in the front

https://youtu.be/2OVUupJ4iqQ?si=gsV0kWIW96R3wLg3

There are some good answers here, but I would also note that because the legal system is adversarial, continued investment can go a long way towards a desired outcome. If you can afford a parade of experts, huge amounts of gathered evidence, and contingency plans researched and prepared by dozens of lawyers and paralegals, you'll do better in court.

It's an arms race, so the "best" lawyers have spent the most on arms. That also means that even the worst lawyers have to invest a lot to keep up.