I just don't understand how in the freaking blazes they can get the phone records of thousands of random outsiders but not the people who were last to see her.
I think you've misunderstood.
They requested the McCann cell phones in the very early days, which is SOP.
They found that the phone's own call registers had been deleted, but one stray had been overlooked. There was a Kate-Gerry call still on one phone not the other.
It was decided at the time that requesting a "tap" on the phones would be too inflammatory (the respective governments were already involved) so they did not pursue the phone angle at that time...also, the PJ are not that wealthy. All this international legal stuff costs money for lawyers which they possibly didn't have or couldn't get.
It is also questionable if a UK phone company would accept any request for it's records from a European Police Force at the time short of court order, so it is easy to see why this angle was not followed up...especially when the parents were clearly POI's.
Now, however, we have Operation Grange, who are clearly attempting to rebuild a record of ALL mobile communications that night, from PDL.
As I noted, it is a small town, with likely only one tower nearby.
Those records, "pings", are permanent and unalterable.
Once the phones that were "pinging" are identified, the next step is to approach the Telco's who supply that particular service with a request for information ie....this is "your" phone number belonging to one of your clients, please give us the call register for that particular number for that particular night.
The providers will have the records that need to be traced, and the providers are only going to reveal those if they absolutely have to...ie, forced by court order.
Now, it seems, that is FINALLY happening.
I have high hopes...this is (should be) finally something outside of McCann control.