At this time, George W. Bush doesn't need to take a United flight to Beijing. But in the future he will when he no longer lives in the White House.
A direct flight between DC and Beijing is not intended for the President, the Premier, or limited number of Chinese/American officials visiting their counterparts. It is for ordinary citizens and businessmen. As China prospers, such a flight is warranted.
If you do not want to make a difference, please step aside and keep your mouth firmly closed. You will make a difference in doing that.