Suffering from "-isms" in the classroom?

I've been very busy with starting college again for the first time in two years. It's very challenging, but I have been running into roadblocks I didn't expect to find in academia. As it turns out, my new department is very prescriptivist, which as a linguist, I find very troubling. However, there are even more things making me uncomfortable.

In my speech and language development class, we've been reading a textbook by a professor of speech language pathology (and a PhD) that I have found very troubling. He uses a lot of stereotyped examples when talking about cultural differences in language development (such as, "Asians are more reticent that Americans in speech") and without providing any evidence other than anecdotal items. That is not hard data! Also he uses "middle-class Americans" as a standard, while omitting race from the information unless he want's to differentiate between what he calls "middle-class Americans" and "middle-class African-Americans". I think he needs to incorporate White in his statements and so-called observations, otherwise his categorizations make no sense.

On top of this, I don't feel like my professor really respects my unease or disagreement with the way this author is presenting his information. I don't really know what to do, and I'm a bit tired of being the only dissenter in the class.

Furthermore my professor recently corrected my writing in a paper as not being "people first language", I had written 'deaf infants' where I should have written 'infants who are deaf'...meanwhile the professor allows a sociology major (!) in class use the term homosexual...which is very clinical and not people-first at all! (In case you are wondering, same-sex or gay/lesbian is more appropriate and "people first").

My last point, we were watching different videos of babies practicing a concept called joint attention with various caregivers. All of my classmates ooh-ed and aw-ed over all of the white babies but during a video of a very cute black girl, no one said anything or made any noises at all. I didn't think about this at first, but I was feeling odd and then it was all bit chilling to me upon further reminiscing. What are the implications of this? I'm not sure.

I'm not sure what to do, I feel like a black sheep in my department. This is all new to me, I've never encountered this in academia before. My undergraduate degree program was in a linguistics department that was very forward thinking, pro-feminist, anti-racist and anti-homophobic, very social justice oriented and active in our community. From what I have seen in this department, things are a bit different. I am not sure how to proceed.