What? It's an inversion. First, 3rds treat consumers like shit. When 3rds treat consumers well, sales came. It's not rocket science. Consumers are the kings, not producers and game developments. I demonstrate that. Your inversion is not accurate because that fault is because the 3rds threat fist consumers like shit, not otherwise. 

Because Horii wants a DQ in sony console, that cost too much to SE and they need a portable backup plan and launch the game too late in 3DS lifecycle. The rule, launch in a leader of sales in Japan is broken than DQ XI have to release in portable too, otherwise will diminished sales. 

It wasn't really that per say Horii said he wanted a home console level game in general I guarantee you if WiiU was successful they would have gone with that but it was clear the platform was never going to take off at that point hence why PS4 was chosen and a 3DS version was made as back up in order to follow the rule which he implemented to maintain the series' longevity. It might be possible the game may have even been in development before they realize WiiU couldn't be saved so things were moved to PS4 instead and a 3DS version commissioned as we know the 3DS version started development after the console version, Horii has had a preference for Nintendo platforms in recent years due to how they helped push the franchise in the west with the DS and 3DS games which is why a NS version was already decided by him before we even knew what the NS was.

The next DQ game how ever the's no such problem as NS is the clear dominant force in the region by miles and can provide both portable and home platform level experience so DQXII is already decided for the platform even before any announcement is made.

Yes. I agree with that. But break the rule: DQ is on dominant console, one per generation. The Horii wish, console stationary dream, hurt the franchise and need a backup plan. 

DQ has kinda died in Japan or is it my impression, last entries have mediocre to bad sales for DQ. I fear DQX damaged the series.

It did like 4 million in japan, there is no way it has”died” in japan or had bad sales. Simply square messed up the release of the game so it did less than pervious entries. The series isn’t tainted 

Knowing Japanese third parties, DQ12 will launch on PS5 but not Switch, they really do seem that stupid.

Dragon Quest XI: Echoes of an Elusive Age

1. 3DS(2017) - 1.772.911
2. PS4(2017) - 1.368.698
3. Switch(2019) - 520.693 

TOTAL: 3.662.302

Only 4 other DQ games have outsold DQXI, and by the end of the year, it will be just 3. 

Anyways as far as 3rd party games, I'm not even talking about blockbusters. Most of the evergreens like Taiko and Fishing Spirits aren't high budget games it's more about delivering something that utilizes the JoyCons or provides great local multiplayer. The biggest omission is the lack of ideas regarding potential titles that would synergize well with Animal Crossing. As I've said these companies are being run with a lack of foresight, they knew Animal Crossing will eventually release,  women will start to pick up the Switch in droves and there isn't any title outside of Miku that's focused in any way on this audience.