Why do people think that we lost the Vietnam war. Our these people ignorant?

I am only 16 and my reasoning makes me sound like a military expert compared to some anti war pacifists. The Vietnam war was from 1955-1975 ( we started sending in our troops in roughly 1964). In about 12 years of fighting we lost only about 48,000 military KIA. That comes to about 4,000 dead each year. The Viet Cong lost over 1,000,000 KIA soldiers (not civilians soldiers). Hell statically it was better than Korea,ww1, and ww2; so when people say that we lost i think they are being ignorant. Our politicians may have let us down but; our military certainly did not. What do you think?