"Tough decisions like this are the way you end up with a great product. It's what you say no to, rather than what you say yes to, that lead to great products."
That doesn't apply in this case. Saying no would have meant they never added it to Firefox. They said yes and now they're removing it. I'm not sure who said it, but there's a saying along the lines of "If you force users to change, they go shopping."
Keep in mind that the definition of "great product" depends on the person. For the average user, a product that does what you want and keeps doing it is a great product, and anything else sucks.
They also said that the features are used by less than 0.01% of users. I assume this is based on their own telemetry. So they're really not forcing very many users to change at all.
That doesn't apply in this case. Saying no would have meant they never added it to Firefox. They said yes and now they're removing it. I'm not sure who said it, but there's a saying along the lines of "If you force users to change, they go shopping."
Keep in mind that the definition of "great product" depends on the person. For the average user, a product that does what you want and keeps doing it is a great product, and anything else sucks.