I’m now making the point that generalizing evangelicals as a monolith that can ‘change their mind’ in unison is akin to generalizing people by race, gender, etc. I hope you are in agreement on that one.

Had your first statement been clear in referring to the subset of evangelicals ( instead of using a pronoun that refers back to the whole, evangelicals ), the statement would not have been properly called ignorant. As it stands, it reads as if all evangelicals wish for Armageddon without delay, which is an ignorant statement.