To Afghani Muslims, we are the Great Satan. 100% of the Afghani population is Muslim, which is just another measure of the zero progress the US has made there in nearly 20 years of occupation.
I don't think many American troops are happy to be there. But, there are lots of Americans who are happy for US troops to be there, killing innocent people in "self-defense".
You have no idea what you are talking about. We went in Afghanistan because the Taliban had taken it over and was using it to train terrorists and were harboring those who took part in 911 and were protecting them. It becomes difficult to leave because we do not want to leave a void for terrorists to come back and do it all over again. Not sure why that needs explaining.