Oh, that's why you don't have an accent -- you're white.
What do you mean by that? You're mocking people with accents now?
This is not mocking, I'm just saying they should speak properly since they are living in America as well.
The first American citizens back in the 1700's had accents; everyone single ancestor of every American today had an accent. The way we speak today in this country developed over generations. Newcomers need compassion and should be applauded for trying to learn a new language, which, if you've ever tried, you know how exceedingly difficult and demanding an task that is.
None of this changes the fact that they should speak properly.
You can't say what is proper or not when it comes to language, as there are languages even older than English which would say none of us are speaking properly. You just seem like you're being racist right now and people would think that's weird.