I'm having a hard time judging which behavior is less mature:

* the student who tried to convert their own personal discomfort into the wildly exaggerated general conclusion that your example was "pointless and useless"

* the fact that you apparently cannot entertain the truism that examples which students can relate to are generally superior than ones that are difficult for them to relate to

* your bizarre implied learning process where criticism and judgement are reserved only for those who already understand a concept. It's like the scientific process, except upside down. :)

Two of these are under your control to change.