"They always say they have a team investigating"....
I'm not sure if you mean to, but you sound as if you are doubting the system through which squadrons investigate mishaps. Every squadron, USN and USMC, has a designated team to initiate mishap investigations in a timely manner (read: ASAP) according to regulations. Results are made public, and are available simply by asking your NATOPS/SAFETY office for amplifying information. But the process takes time. I had a buddy die in an S-3 crash a few years back. After getting tired of the email speculations among our mutual friends, I simply asked our Pilot NATOPS officer to help me get the released accident report.
I agree, maintainers are often not kept in the loop as far as results/consequences of mishaps (one of the reasons the magazine Mech is made readily available is to help alleviate that problem), but you also have to realize that once the "reasons why" are released, aircrew review and discuss the event. Twice monthly, our squadron had a meeting where both Pilots and NFOs went over the official reports for mishaps in our platform across the fleet and then analyzed the chain of events.