i can see both sides of this debate and really don't know which one to support.
IMO, if you are going to choose to live in a country, be it legally or illegally, you should have enough resepct for that country to learn the most widely accepted language (English in this case). But, I know that learning another language can be difficult and a legal immigrant living in the US might have troubles speaking it perfectly. I know when I lived in France for 6 months I appreciated whenever a person could speak English, but I didn't assume they would. What I am saying is that we should understand and accept that they might be trying to learn and they should understand that learning the "native" language is essential.
~Andrew