Not to say that it disproves your point, but may I point out that they were not isolated from the wider society. If they had been all that effectively isolated, then they wouldn't have known about guns in the first place.
To say something is a social construct is not to say that it isn't real, or that we could get along without social constructs. The English language is clearly a social construct, and is clearly very real. It's also clear that if the USA had instead somehow ended up speaking, say, Swahili, we would have probably gotten along more or less as well as we are with English. But I seriously doubt we could have gotten along with no language at all.
I wouldn't say that CDs and TSs "don't 'fall for'" this social construct. I would say that the gender construct in its current form in Western (or USA?) society is something that most people can wear in greater or lesser comfort, but just doesn't fit some people at all. It's like "one size fits most" tights. Some people (like me) can't get them up past their knees.
I agree with you.
Most adults have pretty much gotten used to their "chains" and figured out how to get around while wearing them. If they aren't too heavy or ill-fitting, why would they want to exchange them for a different set of chains that may be just as bad and require another few decades to get used to?