Just a guess on my end, brown shelled eggs are kinda "newer" in the mainstream, I think they started coming out around the same time that like better quality eggs (free range, grass fed etc) did, so I think people associate them? I think it might also be like "well they're brown so they're different and better"?
I mean you're right, a store bought egg is gonna taste like a store bought egg, all are trash in comparison to what you get from your own hens, why people are egg snobs between white n brown at stores I'm not sure, hopefully they taste a farm fresh egg one day though!