Why do people in the us complain the way Afghan and Iraqi militants wage a war against the usa?

i find it funny that we complain at the people we are at war with cuz they don't put on a uniform but when you look at the colonial days when we were fighting the British we were doing the same thing fighting in street clothes while the red coats were fighting in a conventional way! we were the ones not fighting like the rest of the world and this is why we won! now i don't want the us to lose but you have to wonder why it was ok to fight like that and then complain cuz someone does that to us