I like how you combined the cartoons with the story!
I don't know how much I liked the whole relativist angle of the post tho! :P
I often encounter this let's-call-it 'carefree' way of thinking about life, and especially in young women for some reason.
I don't know if you studied philosophy-proper, but it's a recurring joke that all first-year undergrads are relativists (I wasn't, thank God!) One philosopher called it Student Relativism and wrote an article about it! And it caught on!
https://msu.edu/~decoste4/cp/student-relativism.pdf
http://bigfatgenius.com/philosophy/Student%20Relativism.pdf
There's a few points I could discuss, but I'll just comment on a single minor one:
The human brain likes to create and use short cuts to reduce the amount of energy needed to complete tasks.
I think that's very true. And I think it's partly the reason why relativism is the go-to philosophical stance for untrained minds! Trying to explain why many people say things like "oh we're all different, have different values - and all are equally valid", I often land on precisely your explanation: it saves them energy. It's surely much easier to look at all the religions in the world and say that they're somehow all partly right, instead of studying the religions in detail, seeing how they can never be harmonized, and then furthermore studying their claims rationally, becoming an atheist, and then having to live like one, i.e. becoming as popular as a feminist!
Much easier to dispense with all of that and call everything a matter of perspective!