Was the Drayton incident even related to water effects though? If not, then again Alton Towers have drawn attention to something that was not a problem in the first place, like the debate around putting back the Smiler audio.
But if Alton Towers had an existing problem with people regularly standing up in the waterfalls, that makes more sense to stop it until a better solution could be found. But I don't think they are interested in finding a better solution, I think theyd rather cut the water effects permanently because it's the easiest option. All those kinds of decisions is what amounts to a lacklustre park