Action JRPGS will be the brunt of the few JRPG's that get AAA budget. This is because elements of an ARPG are more in line with what's the norm in today's market, number 1 being worlds in which you transition between Town, exploring and battles seamlessly. Turn base/classic JRPG's do not lend themselves with well with those elements. The reason you why should root for JRPG styles that you don't necessarily like is because they are going to pay for more games like Octopath Traveller. The success of FFX or Xeno is a success for the entire genre. If FFXV had bombed there would be not Octopath Traveller (FF bombs then RPG lesser than it goes bye bye). Games like Octo are an experiment that developers would only be willing to take if they know that have funds coming in elsewhere. The fall of Action RPG is not going to propel classic JRPG's back (stupid kiddy mindset). It's going to kill the whole genre. You don't have to like ARPG's, but do know they are important for survival of the genre.
No. I have not to support games I don't like. That's something different than wishing them bad sales, that's not good behaviour for a gamer. But supporting - even purchasing games I don't like is never good.
You also have to accept, that turn-based and real-time split every genre. Turn-based startegy is a different genre than real-time-strategy. Turn-based RPGs are a different genre than real-time RPGs. If I like one, I have not to like the other and vice versa. Gameplay between turn based and real time is so fundamental different, these games aren't comparable. So there is no RPG-genre (even less a JRPG-genre, the differentiate japanese and western games based just on their countrya of origin instead of gameplay is just wrong). If turn-based RPGs die out it doesn't affect real time RPGs at all - it only leaves the fans of turn based RPGs in the rain. The other way around too. So no, real time RPGs aren't saving the genre, as they are a different genre.