i don't think steel is experiencing a resurgence as the favorite material for bike manufacture..
i don't think its place at the top of the pile was ever even in contention, not in the last 100 or so years at least..
i don't know what a 'serious' bicycle is but there's somewhere around 100 million bicycles produced worldwide every year and i think you would have to be pretty narrow-minded to assume the majority are carbon, aluminum, scandium, or whatevium..
andrei padlowski
glen ridge, nj