Comment by antonvs

Right, the point is it's a kind of elephant in the room - they even allude to it not being a common use case - but they say nothing about the rationale. That leads me to suspect it was a kind of "seemed like a good idea at the time" situation.

They also touch on this when they say that it worked for them for a long time.

This is a pretty classic symptom of a system that was designed a certain way early on and then runs into issues as the system grows.

One can argue that this was due to a bug, but it's a bug that they shouldn't really have had to deal with - a consequence that the design opened them up to.