It's not about kids being there in general. It's about how they control themselves. Kids who are mature enough to sit down for a nice meal and not have a tantrum, or run around, are more than welcome. Just like at other more formal sit-down restaurants.
Liken CRT to a themed tea-time. It's supposed to be sophisticated, yet whimsical. Not a loud free-for-all. A lot of the kids there went to BBB and are dressed up in rather expensive clothes. It's all part of the overall ambiance, which lends itself to an elevated experience.