I agree with most of what you are saying, and this leads to the greater argument for a national Police Service rather than the regional system that has been operating since the Police service began. Unfortunately, as with all things, it comes down to budgets, time and the willingness of individual forces to dedicate personnel to such schemes.
I think you may have missed my point about victims not having enough information to hand when reporting a theft. If they don't have the information (such as frame number) then how is it possible for them to say 'yes that's my bike', unless it has other defining characteristics, such as marks, additions and unique, non standard parts fitted, all of which must have been provided at the time of making the report. If someone has, for example, their red Specialized Allez stolen and they report this as 'a Red Specialized Allez and someone else reports a similar, red Specialized Allez, stolen, then how do we know who is the rightful owner of any red specialized Allez's that we may recover in the future.
I think your attempts are great and it's a shame you can't get the Police as a whole to take it on board and assist.
What I do find difficult to accept is how hard it would be for the bike retailers to record frame numbers of all bikes they sell with the details of who they sold it to. I say this because I contacted
Halfords with regard to the bike we had recovered to see if they kept records of who they had sold it to. I was told that they didn't do that. Why I don't know. It would take very little effort on their part to do this and it would assist greatly in returning bikes to their rightful owners.