The "America vs Europe debate" only ever pops up when an American comes into a thread telling everyone how wrong they are. As you say it is ironic because the position that there is one "Europe" to compare the US to is one that can only be formed in an environment of ignorance. Asking why was at some point useful, but given the pernicious nature of these discussions and the vehemence with which they are repeated we have to assume they are not going to go away (unless perhaps we ignore them).