I learned about map projections in school, although I don't recall in what grades. It would have been in the late 1960's or early 1970's. So I was rather puzzled the first time I heard Mercator criticized for bias. The criticism came from a politically conservative acquaintance who objected that it made Russia look too big compared to the U.S.! As you say, we project our own views onto the map. People are way too quick to see bias and prejudice in everything. Not that bias and prejudice aren't real and don't affect things, but often when we look at the mirror of the world, what we see is our own biases and prejudices reflected right back at us.