The short answer is, IMHO, some people simply look for things to make issue of and start a fight over....
First of all, thank you for your service to our country, I appreciate it!
I think for someone like this man to find answers in Islam, he would have an innate hatred of America. It's easier for me to understand why someone in prison might be converted, someone with an inner rage against the system - but I don't trust someone who has enjoyed the opportunities this country offers and then puts their faith in Islam.
Such a man cannot have good intentions.