Earlier quoted context omitted.
I think your are mixing “English, the lingua franca”, with “English, the language spoken in the US”. Why would using the lingua franca that everyone agrees on be imperialism?
Because there is no such a thing like “English, the lingua franca”; changing the name do not change the content. We should stop self-deluding ourselves in believing that English exits in a geopolitical void. English is the language of the anglosphere, and speaking English is a huge favor to those economies, and that comes with a sense of cultural inferiority as well, in many peoples.
Aviation is a curious industry. English is commonly spoke between flight crews and ground stations world wide (with few but notable exceptions). Circumstances where the English meaning of a word wasn't well understood by the flight crew or the wrong words were spoken have, on occasion, lead to disaster--Avianca Flight 52 [1] comes to mind, among others.
I simply cannot agree that mutual intelligibility is bad simply on the merit that it somehow creates a "sense of cultural inferiority."