Not only scoff at the idea, but often discount it as completely invalid because while pointing out the flaws of our current system you didn't also spoon feed them years worth of theory breaking down all of the potential new systems and produce a dissertation for them detailing every single step from pre to post revolution.
They never look any of these things up themselves of course, because they don't actually care, they're probably just comfortable enough under the current system to believe that they have no personal reason to fight it, and don't like their cognitive dissonance being challenged so making up reasons not to listen or really make any effort at all is easier.
And if you do give them entire essays worth of data, facts and arguments for change they will dismiss you, probably call you a commie and generally respond with "I'm not reading that"!
I'm on the side of social cooperation but this "argument" is pretty damn flimsy.
Scenario 1: I donate to some go-fund-me to pay for some kids medical treatment
Scenario 2: I say "we should all be forced to pay for public healthcare for all"
I personally am very much in favor of the latter, but being happy about #1 and against #2 is not some kind of crazy cognitive dissonance.
I think this is more directed to conservatives who claim people are inherently selfish and self-serving, which is why only capitalism works (because it starts from the assumption that people are inherently selfish and will always do what profits than the most) and communism / socialism / anarchism can't possibly work (because they require people to cooperate instead of exploiting each other for personal profit)
Besides, the idea that "we should all be forced to pay" for anything presumes a capitalist system where money is exchanged for goods and services. The point is to get rid of that.