Bnei Brak is, for all I know, a way to live a segregated (as in, among equals and without foreigners) and religious life.
Heck, most Israelis I've spoken with (and 95% of my contacts here are ~secular~, more or less) avoid it, claim that I shouldn't go there on jewish holidays and certainly keep my wife out of it.
It's considered off limits for most of the non-observing population that I know. A (large!) ~ghetto~ next to the (secular, touristy, ~gay~) Tel Aviv.
> Before cars, towns were organized for churches or shuls to be within walking distance which means segregation.
It's not gone. Some areas of North London are full of kosher delis, men with black hats and side-curls, etc, some don't have any.