Obama Bows Too Deeply

The US President Barack Obama bows Saturday while he greet Emperor Akihito at the Imperial Palace.
However, according to U.S. conservatives, he bowed too low.
Many countries have its own unique way of greeting.
Therefore I think it is hard for foreigners to follow different customs just like the way native people do in the country.
Maybe the president bowed too low, but I think he just wanted to show his modesty. Besides, he looks very polite the way he greet to the emperor.
Some U.S. ex-presidents had also claimed by the conservatives of their way of greeting in foreign countries.
They should not criticize the president too much, since some people have hard time following the custom of different countries. Rather, that can happen to everyone.