There was never any implication on my part about your experience (as I don't know what it is), but of the bloody stupid default setting by MS that doesn't nothing but confuse when the user whoever that might be when they 'don't know' what MS considers to be known extensions.
MS aren't really 'doing no harm' as you say as what harm is done by displaying the file extension, none, as the file name is displayed in the explorer view but not the file extension, so you end up with a bunch of file names (some the same) with no extension displayed, which only serves to confuse. There is some mileage for hiding system files from the novice user to avoid possible deletion, etc. but not hiding file extensions of known types IMHO.
I have never used Apple computers since that is the case, no OS X experience as they fear the damage releasing OS X would do to their otherwise hardware sales. No Mac, No OS X (legally)