It's crucial that criminal proceedings don't start messing up accident investigations, as they do for example in Italy; however, it's reasonable that those who have suffered damages should be able to start to seek civil redress.
There are families who've lost parents, partners, income and security as a result of this accident. While it's not clear it was anyone's fault, it certainly wasn't theirs, and they start carrying the burden when the crash happens, not when the AAIB determines the cause.