I get your frustration with this, but be careful what you wish for, especially if you only get part what you wish for. If they go back to hard and fast (but smaller age groups) but keep the frequent Open House hours (which as the PP pointed out, many families like since their kids don't want to go to the clubs alone) then what you will have is more hours when you can't drop your kids off at all, or worse, very few hours when you can drop ALL of your kids off. To me, that would be even worse than the current situation of all the dropped off kids being in one smaller area. Suppose, for example, you have one child that is 9 and one that is 4, the only time they could both be in secured programming is when neither of the Clubs were in Open House. I think a lot of people would complain about this even more than the current situation.
Now, i realize your response might be "Less open house hours" but remember, they are trending towards MORE Open house hours for a reason, and that reason is probably because even more people have said they want access to the kids clubs with their children, or with their siblings. So that trend won't change lightly.
Ultimately, I think we have a case where most people would be happy with either configuration (3-12 or two separate age groups) and there is a vocal (and reasonable) minority on each side that will be unhappy as long as the policy is the other way. My sincere sympathies.