Because Flipkart is one of the biggest sites in India. Firefox devs didn't want to ruin the day-to-day web browsing experience of so many people, so they revert

Because Flipkart is one of the biggest sites in India. Firefox devs didn't want to ruin the day-to-day web browsing experience of so many people, so they reverted the change. They preserved the user experience at the expense of the developer experience, and I think that was the right call. Doesn't matter that it was Flipkart's fault.