That's probably valid criticism of Spain, but in fairness, it's not like Catalonia was asking for more autonomy. They have been aiming squarely at secession, for a couple of years now, and that can be seen to be limiting Spain's options quite a bit.

For example, you say that they could have had input on the wording of the referednum, but if Spain is not going to accept secession on any terms (and territorial integrity is one of the most important sovereign rights in the current international system, so that is reasonable on their part), then what would be the point of having that input?