I'm sure they've already got something like this planned but the solution is pretty simple:
In single player you accumulate dispatcher xp for performing the role of dispatcher correctly, as you get more points increasingly complicated dispatcher positions on the multiplayer servers are unlocked. Simple.
I think most of the problems are people at SG not realising they are controlling a junction and that they actually need to read where the trains are supposed to go and people fiddling with the running direction of lines such that traffic is queueing up at certain key locations.
Don't dumb the signalling down, keep it realistic, there are enough of us that are capable of doing it properly, just lock it behind a decent level of experience required.