Gosh I hate hero images so much. Wasting anywhere between 30%-100% of the above-the-fold space on an often completely meaningless stock photo or illustration with a loose connection to a keyword — who the fuck likes that?
Reddit's old vs. current design is probably one of the biggest examples of the user philosophy changing overtime. Not really a "hero image", but the focus of presenting text with small thumbnails to huge thumbnails and a small header likely follows a similar philosophy.
I love hero images, but I get that on many sites it pushes the actual content below the fold, which isn't ideal.