Due to cultural expectations, some defensive arms have more credibility that others. For example, a young woman wearing chain mail and wielding a sword would not be taken all that seriously by many. The look is too quaint, and there no certainty that she’d be competent with her weapon. Never mind that a sword can be extremely effective at close range. This lack of credibility is aggravated if the defender is old or infirm, or if the sword is replaced with a knife or a baton. The probability of of the defender having to actually fight against an unconvinced attacker is higher than with a firearm.
The same person with a ranged weapon and multiple shots on tap would be taken rather more seriously. She may be clumsy or only slightly trained, but she would still have 31 tries at poking very deep holes through her attacker at standoff distances. So carrying a firearm would win more fights by default from the foe — and be easier both on the defender and the local ER staff.
Carrying a pistol concealed is also rather more socially acceptable than clanking along in armor, with a sword on your side.