Nothing wrong with this way of greeting, if you happen to be where they practice this custom, or if you happen to be at some cultural event.

Great for Asians who grow up with it. But, I don't think it's ever going to catch on in the U.S. I fail to think of one reason why it should.

I sort of wish people in general could learn more cultured methods (such as this) of greeting one another -- not all the time, but just as a change of routine. But the parties involved should be sure to stand at a reasonable distance from one another.

In many Asian cultures bowing of the head head or upper body is used in much the same manner as shaking hands but with perhaps a little more cultural reverence. Many have adapted the western habit of shaking hands when dealing with westerners but for the most part this is ingrained in their culture.