For what it's worth, I read something once, and I am just summarizing because I don't remember exact wording or source, although it's a legit one I am sure, mostly true for the east coast, but I assume other places as well. Perhaps there are a lot of cold hardy brown egg layers?
White commercial (read leghorn) eggs were trucked in, while local farms tended to have brown egg layers (again, cold hardy? what color does a RIR lay?) so people associated white eggs with a lack of taste because, and I am sure we can all agree on this, they were not as fresh due to being shipped in from elsewhere. Where as brown eggs came from local farms, (read fresher) and therefore had a better taste.
I think this "wisdom" has been passed down that brown eggs are better tasting, and that's where people get that brown eggs are better, or really "fresh from the farm" as opposed to white eggs.