I've worked with Americans of all services in my time and now that I understand their system of medals, ribbons and badges I'm a fan.
Firstly don't try and compare it with the UK system, they are apples and pears and what works for them might not work for us and vice versa. With the US system you get to see an individual's military CV on their chest, especially useful when in a meeting and needing to ascertain someone's credibility or walking into an office or ops room and needing to ascertain who is the "go to" guy.
At Aviano I went to the MT office accompanying a USAF officer who looked around and then walked across to a particular airman, asked a series of complicated questions, got the answers he needed, thanked the individual and walked out. As we walked to our car he said how easy it had proven to be once he spotted the Outstanding Airman ribbon on the airman's chest as he knew he would be a quality individual able to deal with his particularly obscure query.
In my opinion the US system is neither better or worse, simply different.