Not to be critical, but, are you sure that they aren't doing just that? We are only in those places for a small amount of time and they cannot be expected to be standing there and wiping them down constantly. They can, however, expect parents to not let their kids lick the screens. Yea, I know, being a parent comes with a lot of responsibilities that are not transferable to someone else. They will be grown up soon enough and one will miss the process no matter how much of a burden it might seem to be right now.
Please understand, since the "licking" process came from another post, I am not being judgmental about this. I know how tough it is to always see what is going on every single second of the day, however, if it is not possible for us to completely watch our children and keep them 100% out of harm, why would we think that Disney can be given the massive responsibility to take care of our children when we can't. I would seem to me that we have a lot fewer to watch then they do.