Well the logic being It would simply create two tiers of indian customers.

One a set of well paying, hygienic, Indians many of whom are born here.

And the second a bunch do fresh unshowered immigrant uber drivers that are trying to get discounts on a root before the next drive.

And that lets the girls themselves distinguish between these two groups.

If Ginza wants to expand at some point they probably will run into a cap of customer base and so this seems like a no brainer way to unblock that.