I disagree on the handhelds part, all the Kingdom Hearts titles generally draw out the best -or nearly- from the relative console. Hence, in my opinion, the handhelds titles are just as worthy as the numbered titles. Furthermore, even if it was done mostly for commercial purposes, having Kingdom Hearts titles on multiple consoles keep the series a lot more interesting, fresh and enjoyable! Every Kingdom Hearts installment has its own charm also because of the features of the respective console, it wouldn't be the same if they were all released for the same console. I agree with you for the Kingdom Hearts III part, I would be surprised if it were to sell poorly.