Ok here's a better explanation of why this bugs me.
They come up with a thing that doesn't exist anywhere else. A monstrous creature skimmer, for example. It doesn't occur to them that there might be some snags with this that need to be ironed out. It would be fine if they just told us exactly what a hoverer was right from the start, and maybe made it a USR to apply to stuff like Tau drones as well, but that isn't what they do. Without the update we would have Talos floating above terrain unable to enter it, and a faq is required to clarify that attacks against it in CC don't always require a 6 to hit.
We do now know how the talos works but the irritating thing is that GW never realised that there would be a problem. Worse, they very often reply to questions with something like "well obviously it works like this..." when it's not obvious at all, and it's their fault that it isn't clear.
Of course Lash of submission is the most recent example of this. Hey, let's give people an ability they have never had before, moving enemy units, and let's have all the rules in one short paragraph. Let's not bother clarifying whether the models in the unit all have to go the same direction, move the full distance, go in straight lines and so on. Actually let's not even consider how players might use the power to scope or range snipe characters and special weps, to bunch units for blasts, to set them up for assaults with their hidden power fist out of the way, or whatever. I'm sure this won't cause any arguments at all.