Americans now understand that to be truely comfortable in the tossed salad of American life we have to know who we are and where we come from. An added benefit of day school ed is the package it delivers. All your child's educational needs in one place. No PM Hebrew school or Sunday morning carpools. When it's a Jewish holiday, school is closed, so you don't miss something for preserving and honoring your heritage.
Day schools are also independent schools, able to make their own decisions and adjustments.
This makes them more responsive to learner and parent needs and expectations. This is Mindy in Phila. As for having everything in one place. Putting everything on one campus can be exciting and cost saving. The schools can use the athletic facilites at the JCC and a lot of synergism can take place.