I don't think you have to speak English but it's more so just to make things easier. English is the predominant language in America so I'd prefer if people were able to speak even a tiny bit(imagine the X to English dictionary). If I were to go to a foreign country where it's predominant language isn't English I will at least try to speak it even a tiny bit.
Now I'm not saying that you have to speak English 24/7 bc if you're not talking to me then it's none of my business what language you're speaking.
Sure, it makes thing easier but they shouldn’t get threatened to be deported for not speaking it.