Nah, we don't think that makes it ok, but there is really non intended and we know how easily Americans can get hurt.

You are right about the stereotypes. Used correctly they are a wonderful tool for anthropological insight. And, of course, there are tons of stereotypes about any group. This time the situation just fit the stereotype to a T and that made it funny for me.

The carbon footprint increases due to the rather disposable nature of the blanket and the fact that it is most likely not used only on the plane. Besides that, whether the carbon footprint increases i.e. the actual output depends on the load on the alternator. Like a car driving with the AC on uses slightly more gas. Naturally, the blanket will put a minimal marginal load on the alternator of an aircraft. However, in principle, it is a device that uses electricity versus a device that conserves energy.

Not to have this degenerate into an American bashing thing, even if this time the American rationale is off. On many things the Americans just win hands down like practicality, convenience or less bureaucracy.