Because one, this game is not going to be doing well if they keep fudging design changes. It took them 3 attempts to get the targetting system right; if they had told people of their plans beforehand, someone could have corrected them and they could have gotten it on the first try.

And two, even with the minor details that we get, we can analyze some things. Complaining about stuff you can't grasp IS bad. Complaining about stuff that's stupid or just won't work (i.e. kicking retainers out of wards based on a set of arbitrary rules) is good.