There was a time when "dressage" was elitist. Lots of us learned to ride the flat because it was in between the jumps. . . I don't think dressage as it is often interpreted is the be-all: now, I absolutely love dressage, and I don't jump at all any more, but I can remember when riding wasn't riding without a jump somewhere. I can remember when we didn't collect our horses except on tight corners. We rode forward seat, and let the horse move in a long, natural manner. In those tight corners, though, hm, we learned about leg-yielding, balancing, shortening the stride, all interesting things that you MIGHT call dressage.
Anyway, while her disrespect is unacceptable, I think you might go easy on the Must Do Dressage routine.