I don’t see it as sour grapes, just mis-judgement of what matters to new buyers as opposed to existing Genos owners.
Learning curve matters, but if you take that away, this new Korg is certainly an attractive keyboard. Yes, you will find some voices or styles on the Genos some like better, but both seem overall great sounding keyboards, and no-one buys one keyboard over another because of tiny differences in a few voices. If the voice is already pretty good, how you play it matters much more than if the voice is slightly better.
Korg may have an edge in some technical features, certainly in appearance, and a fully weighted 88 key is unmatched in a portable arranger.
Does that relegate Genos to a poor second, - definitely no, and some of the things PaX5 offers may matter little to many existing Genos owners, probably not enough to jump ship, ….. but it will be interesting to see how Yamaha responds.
Mike