TL;DRReverse the sorting order of the two signals in the crafting/filter menus.
What ?Introduce chain signals for the entire network (forcing trains to reserve the entire path) as the simple, guaranteed deadlock-free (train won't move unless it can go the whole distance) signaling method, with rail signals terminating the chain as an advanced optimization which can introduce deadlocks with the benefit of additional throughput.
Failing that, it makes sense at least that chain signals look ahead to the next signal, and putting them before rail signals would fit this outlook (L-to-R reading bias notwithstanding).
I would like to see a version of the rail tutorials approaching signals from this perspective, introducing chains first, then rail signals as the more advanced (and potentially dangerous) topic.
Why ?Factorio players learning the rail system for the first time often build systems that work and then suddenly stop working when trains get stuck facing each other in a deadlock. Furthermore, the chain signal seems mysterious and confusing, and it's not clear where or why they would be useful.
If the chain signal reserving an entire path were the norm, then rail systems would at least work with any number of trains (as long as there were enough free paths and stations). Throughput would decay with time, incentivizing the learning and use of rail signals to mark safe-blocks.