I agree. Transitional and prelim interviewers know why you're there; they know you're not going into medicine or surgery. I chose to change a little part of my PS to reflect this. In my anesth PS, where I wrote why I thought their program would give me the springboard I wanted, I just changed it state why I thought their prelim year would give me a great background for my chosen field. It's one sentence, and probably worth the work simply to avoid appearing lazy or thoughtless.