They probably overshot with the changes, but it's not a feels bad way to empty out everyone's cash and items, as opposed to straight up deleting them and starting over.

What else are you gonna spend cash on if not the girls and stats. The number of girls I need to get from 2* to 3* has been whittled down to 5, once they are done and the new girls are both 5*, cash is gonna build up again. The game doesn't really have a true gold sink except for the pachinko, where you can put cash in for maybe an upgrade.