This post is bizarre to me. I've also seen quite a few shows at Steppenwolf and all the other equity theaters and haven't really known them to tone down language or shy away from nudity. I agree that occasionally this happens... but I wouldn't say it's common.
Each Steppenwolf season in the last ten years has had at least one show that's either had nudity and or very graphic simulated sex scenes. And Tracy Letts and Bruce Norris are both playwright ensemble members... so... course language doesn't seem to be a concern.