“Never” is carrying a lot of weight here. Leaving people out can be super effective, especially if they’re not needed for a task. They might be needed in 20 minutes when it’s time to do their thing, but if a group doesn’t need that person and can communicate more effectively without using that persons language, there’s no need.

Imagine an EMT crew. All of the medics speak Spanish and the ambulance driver only speak English. He needs to know how to get to the emergency, and which hospital to take the victim to, among some other things I’m sure. But I don’t want my all Spanish EMT crew fucking around in English and miscommunicating with each other just to make the driver feel more comfortable.