For extremely busy restaurants / cafe's where people are already waiting long periods, they probably don't want to overcomplicate things too, and increase the risk . They'd have to keep 2 different milk frothing machines, and every time a customer got sick, risk getting sued, whilst slowing down the efficiency of orders.

Whilst it might increase the number of potential customers, in practice, it might only have negatives

That is the standard response in France, I'm surprise that waiter was so polite about it.

That's probably the most polite barista in Paris. I'd have expected a tirade, complete with arm waving and rude gestures.

I love France and all, but let's not pretend they have good coffee culture. What passes for cappuccino there... The horrors I've seen.

The waiter probably was conveying it's not on the menu or is out of stock. No big deal..

Ah, the french.

Don't know where europe would be without them.