Newsflash for Rich: Not all mechanical engineers are men and not all of the mechanical engineers I worked with were men. Furthermore, I currently work with a graphic designer who can spell but has problems with proper grammar. Based on the information I've given you, do you think this person is male or female?
Yes, writing is a nice skill to acquire to those who wish to acquire it and those who have the aptitude for it.
Finally, offers to proof read and edit can be stated in ways that make them appear to be offers and not put downs. To me, "I see some mistakes in your text. Do you mind if I correct them?" sounds a lot better than the statements that I read in this thread.
Just as the rest of you are, I'm finished with this discussion and am moving on.