Why do people like to use exceptions to disprove a rule?

If i say that men in general are better in combat, people will say "well i've seen a woman do this better than men in combat" as if this somehow disproves the general rule that men still do combat roles better. Or if i say that in general women are better when it comes to taking care of babies and little kids someone will say "Well I've seen men that know how to take care of babies". A couple of men disproves the general rule that women are better at taking care of little kids. People even like to use themselves as exceptions
Why do people like to use exceptions to disprove a rule?
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