the OP forgets one little thing that made the eradication of the James Gang by a bunch of farmers who loved long range target shooting in minneapolis, is the fact that
the citizens had the weapons, the warning that crap was coming, and that the citizens had absolutely no qualms, "buts", or "ifs" about defending their town and life savings in the bank.
few people TODAY have the brass to VOTE for what is right, let alone to actually get off their ass and do somthing about. Most people still believe in "if the armed criminal wants something, give it to them in order to keep the 'moral" highground".
And arming the neighbors is in theory a nice thought but however to many issues arise with it.
some states require the OWNER of the weapon to have it stored in a safe in their own home. hence letting the neighbor keep it in their house is a legal no-no.
liability. can not get over that fact. if your weapon is used in a crime, they simply consider YOU to be the culprit who knocked over the gas station and killed the 3 clerks in the bathroom.