In the case of French fries, French bread etc. the "French" part actually refers to origin of the recipe/preparation method, rather than where they are produced today.

The origins of the people and culture of the USA are based in the UK and Europe, so they would lose much of their heritage by shunning it.

The country is relatively new in historical terms, and everyone and everything not connected to the Native Americans was imported from somewhere else.

There aren't many countries that haven't imported at least some of their people and culture from elsewhere, either willingly or from being invaded in their past.

It would be virtually impossible to sort out who and what came originally from where, and it would do more harm than good to try.

I guess even in the global village, neighbours fall out when one of them forgets to return the lawnmower.