Speaking from an In Game perspective I agree with what De-Legro and others have said; there are explanations that can be deduced from their behaviour and they have little reason to explain their actions.
However from an player perspective I think that Antonine has a point. When the Zuma were actively interacting with the southern realms; interacting with explorers, sending ambassadors and the like, things were far more fun and interesting. The Zuma were adding an interesting element to regional roleplay as well as Dwilight as a whole.
But after the raid on Paisly and the sudden change in Zuma attitudes that followed, IMO they ceased to have any active impact on Dwilight role play or atmosphere. People journey into their lands and get no reply, and when finally Garret emerged as an ambassador he made it clear that the Zuma wanted little to do with the rest of the world. Aside from solitary remarks from Garret (which are often aimed specifically to dissuade any kind of interaction with the Zuma) and the single rp event in Nightmarch (which I will say was interesting, but unfortunately not really followed up with anything as far as I am aware) the Zuma have essentially become dead to the world.
I don't think its worth making a fuss over; I'm sure there are reasons that the Zuma are nigh inaccessible and it does, as others have said, make IC sense. Certainly we don't have any kind of "right" to expect anything more, and of course the Zuma should and always have been mysterious. But I will say that I feel that the old more interactive (yet equally as mysterious) Zuma actually added to Dwilight whereas the currant isolationist Zuma acts as little more than a landmark, no matter how much effort characters might put into trying to get some more interesting rp out of it.
