Easy answer.

Money; If people are paying 5$ for the golden ticket; that justifies the cost and labour to keep that system going and the extra horsepower and labour to maintain the "upper class" neighborhoods. People would pay more for such a sure thing I imagine.

Also to answer Raim - you can actually pay 2$ for a extra retainer for 30 days; you can do this multiple times through the mogstation "retainer service" I know folks with oodles of retainers. I admit the different subs were never really a thing for me as I guess I somehow always was on the old system?