The person saying that, though, is basing his statement off an assumption that the lower classes are inferior in the first place... after all, that's how you can determine that good grammar is a sign of good sense. I suppose it's not explicitly stated as such, but it's a fairly transparent ruse in all cases I can think of. I agree that your version is probably more appropriate for your intentions.

I'm generally annoyed by the reading of race constructs into fantasy or science fiction. As Zoe keeps forcibly pointing out to me, "new" racism is focused on culture, and (in your example), the orcs are culturally more similar to Nazi Germany. Saying that they have dark skin and therefore Tolkien must have hated black people is a pretty pointless criticism - it ignores all the themes that actually make the orcs scary.

In the end, I don't think that sort of reading adds anything to the reading experience; in some cases (C. S. Lewis, for example) it ruins the enjoyment of the work totally. Far better to find and promote authors whose values the critic does agree with.