Agree 100% with that statement, except it wouldn't work for everyone. For instance, I could see a hippie-liberal type saying
"I'm happy with the level of protection the police can give me, man. If someone gets to me before the police can help, I'll just offer them a bong hit and sing koombaya with them. Besides, everyone else here has guns, I'm safe among all of you people."

So I'd say it needs to go a step further: "...everyone would have to BE ARMED AND TRAINED and participate in the security/safety of the community."
I think it'd take a developer to build such a community, with an eye toward defensibility (ie, on a hilltop, and using the natural terrain where possible to aid in defense, with visible and defensible road into it, etc) then lay out where the houses are with an eye toward defense (fields of fire, minimal blind spots with natural obstacles like bushes in those that can't be avoided, etc) build the houses with defensible construction (ie each house has it's own well, solar and low voltage lighting throughout, brick or block or rock walls, non-flammable roofs, corner windows that double as firing positions, full basements with lots of storage space, etc) then add community features (ie, clubhouse meeting area with more underground storage, perhaps a network of utility tunnels that connect all the houses underground, community game fields that could be used for larger events, fields around outer perimeter that could be planted with crops, extra wells already sunk and with windmill water pumps for irrigation if needed,etc).
Then people have to sign bylaws before they can purchase there, agreeing to the above.
This is the kinda thing I'm thinking of, and I suspect if someone built it they would come. I'd sure as hell look at a community like this waaaaaaay faster at this point than I would any other kind of neighborhood. And all those community facilities/fields etc wouldn't be that expensive if spread across the purchase price of many homes .