This question sounds to me like you suspect some outright evil getting projected here. That would go too far. The wayland project tried to get the support of X developers early so that they could become a sort of "blessed" X successor early on. Plenty of earlier replacement attempts have failed because they couldn't get bigger community support, so this had to be part of a successful strategy. Any detrimental effects on X from that move were never a direct goal, as far as I am aware, just a consequence.

Wanting developers to switch projects doesn't have to be malicious, in fact personally i doubt there were any bad intentions in place, the developers of Wayland most likely think they're doing the right thing.