There's some truth to that David but again as Stefan pointed out Shoji Nishio and his senior Yudansha were not big....He was rather modest in stature even for a Japanese person. He handled me and everything I could throw at him with ease and I am 6'2" 250. So I had to be at least 70 or 80 pounds heavier.
When I share the mat with anyone big or small I show them how to "cut" and "lead" Uke never "push" just the way my Sensei does it.
I do agree that pushing in most cases is the lazy Nage's way to make a technique look "good/real".