Ni no Kuni II sold over 900,000 units in two months, so I don't think it's accurate to say that it sold like crap. Also, funnily enough, this is an example of a game that DID try to do something to set itself apart (and arguably cater more to the West) by moving more towards action combat.
I don't think it's a foregone conclusion that Dragon Quest XI will fail to make inroads in the West (like everyone on the show seems to believe). For all of Square Enix's questionable decisions regarding the series, they did address the biggest asks from Western fans by 1) including voice acting, and 2) having a day and date release on PC (which should also indirectly address the issue of the MIDI soundtrack and is something most Japanese third party releases still can't get right), so it's not like they spent this last year doing absolutely nothing or failing to make the release better in ways that may not have been achievable with a worldwide launch. Going to another recent example, Fire Emblem Fates came out 8 months later in North America (and almost an entire year later in Europe) and that game still sold very well, so I don't believe this is as big a deal as it's made out to be in general (especially since Dragon Quest XI is coming out 13 months later, not "18 months later" lol).