I agree actually. I see no tangible reason why certain sections of the MATS Part 2 (instructions on a unit by unit basis - one for Scottish, one for LACC, one for MACC etc etc) can't be distributed sensibly amongst airline ops departments, as long as they were used for reference purposes only. You are our customers after all
In fact, if memory serves me correctly, I think they actually may be?
There are a multitude of standing agreements between sectors, and between units, as someone else on this thread has stated. Amongst other things they're to ensure you keep out of other people's airspace, so they more often than not coincide with sector and/or centre airspace boundaries.
Why not try to arrange a visit for yourselves to MACC, ScACC, LTCC or LACC to see the whys and wherefores of why we have them, and how they facilitate your safe and expeditious paths through the little bits of sky we each have. Most units accept visits from aircrew more than happily - this is definitely the case at MACC.
Alternatively, have a word with your Ops departments and see if they do indeed get any gen from our ops departments. I seem to recall there is a fluid passage of data between the two, but I could be wrong.