No, more that American hotels are a lot larger than European ones (I'm from the UK) and I assumed (with no real evidence) that Americans carry more luggage.
Although it is true that Japan is a bit of a struggle if you are overweight or especially tall.
One of the best room I ever had was in Norway. It was at most 3 times as large as the queensized bed, had at least 5 different lighting options and a fantastic black-out curtain (this was needed above the Arctic circle) and tons of small storage places and hooks - and this includes a tiny bathroom. Everything you need, and super cozy.
Although it is true that Japan is a bit of a struggle if you are overweight or especially tall.