Oh, not true! Asian students who speak very little English often still excel in math-based courses! I've seen it.
All the more reason to take up the analogy that math and language go together much like properly guided religion and science.
I realize there is a need, or so it seems, to compartmentalize education to a degree for the sake of focus, but maybe we should be asking ourselves "why do we do that?" I consider it to be a wholesome thing when the disciplines of language, math, history, science, citizenship, and properly guided religion manifest themsleves in an individual, because any of these disciplines can, and will, come into play at any given point.