I read comics, although not many Superman titles, and have seen the cartoons and the Donner films countless times. So I feel like I've seen the Superman origin thousands of times already. Accordingly, it's difficult for me to be objective enough about this to say what the "average movie goer" (my favorite make believe concept used around here) feels. But I can't imagine anyone would be willing to have adult Supes sit on the sideline for the amount of time it would take to get through a straight forward origin that takes up a large part of the film. Even heavy use of flashbacks would tax my patience. We may not have strictly seen an origin story on film in 30 years, but SR more or less renewed that version - and it didn't even give us a fully formed Superman in action but spent its two hours reestablishing him and his current world - which makes yet another retelling of the origin feel that much more like spinning wheels. At some point you just have to get on with it.
Assuming a reboot, if his origin is needed for story purposes, get Superman up and running in one good film with out it, and circle back on it during a second film after viewer goodwill has been reestablished.