I’d honestly like to see why you think this is the case. Like which third party exclusives are you thinking of that Nintendo fans didn’t support? Because by all accounts from Momotora to MonHun to SMTV those third party games are selling really well on Switch.
"Nintendo fans do not buy 3rd party content". Traditionally Nintendo fans BEG for 3rd party ports. I know I have been guilty of it in the past.
Anyway, Nintendo's 3rd party content usually sells a fraction of what the game sells on other platforms, say Playstation, Xbox, etc. This is not always the case mind you....but more often than not.
Monster Hunter is an excellent example you mentioned. Built from ground up with Switch in mind, and it runs well, and looks fantastic for a Switch title. Guess what...it sold like gangbusters for Switch.
SMT V is somewhere close to a million units sold per reports. That is great for an SMT title, but in the grand scheme of things for Atlus, no where near Persona sales levels. It is extremely niche RPG, so that must factor in. (More niche than Persona)
Still though, Atlus says it has "met expectations" but, it has not exceeded them. So...if placing these titles on PC later helps Nintendo secure more of these titles...do so. I don't care if it is SMT, Bayonetta, Mario Rabbids, MUA3, etc...these should ALL come to PC or even other consoles later to maximize profits.
Some games fall victim to circumstances, which I honestly believe is what happened with Overwatch. Overwatch may be the best 3rd party "port" on Switch. Sadly, it was digital only, came 2.5 years after PS4/Xbox/PC versions and launched without any marketing at the time, because of Activision troubles with China. I believe it still has sold over a million units per reports. But a million in sales is a tiny fraction of what Xbox/PS4/PC sold. If a million copies is the threshold for a "good" amount of sales for a AA-AAA port...then some like Fifa, Bomberman R, Witcher 3, DQXI, all achieved this...
...But many titles do not do this. Most actually do not. This goes back to an age old argument. Does a console manufacturer NEED 3rd party content to survive?
History up until this point has shown us no console manufacture can survive without some 3rd party support. History is littered with the console sales numbers....Neo Geo, PS Vita, OG Xbox, Wii U, Saturn, Dreamcast, etc. Systems that didn't exactly have great 3rd party support. These were different generations, but the trend continues.
With each generation AA-AAA games become more expensive to make, and thus less games are made overall. Switch is great example, look at how many true AA-AAA 3rd party titles are on Switch. Not that many overall.
Nintendo, in light of this has flourished with Switch because they have opened the Eshop and turned it into a console version of Steam. Anything and everything for sale, and Nintendo takes a cut. Like Google, Apple, and Valve. Caring very little for content quality! For the most part. Most of the titles are garbage. There are some truly great titles, don't get me wrong and many of you will respond with what about "Title A, B, and C". You are right! But for "title A, B, and C" there are 20 garbage titles on the eShop.
I have been pushing this narrative for 5 years and now I actually talk to developers about this and safety of online for children. Nintendo should double down on unique content with a few exceptions for 3rd parties (sports, Minecraft, Fortnite, etc.) Make the majority of 1st, 2nd and 3rd party titles
"EVERGREEN" and have
LESS RELEASES OVERALL. I know what I just said. Have the "Nintendo Seal of Quality" or some other metric brought back and stamp that on these titles.
The problem is...if Nintendo fans don't support 3rd parties currently they can not gather enough data and analytics to pivot and create a bold move like this going forward.
Nintendo has no doubt money hatted several of the 3rd party titles on Switch. They can not money hat them all though. So, for consumers, they need to reward the ports that are brought to nintendo that are good ports (whatever your own unique taste). Should we reward bad ports...no. Good ones, absolutely. But if we continue to port beg and not buy those ports, it is still driving the narrative that "Nintendo fans do not buy 3rd party content".
Gaming is at a true crossroads. I truly believe Nintendo offers the best 1st party content due to it's uniqueness and usually high level of polish, and quality of gameplay. They usually also are not into annualized releases for continuous cash grabs.
The end game down the road is nintendo will likely be sold to a larger entity. Will it be in 10 years or 50 years. To give Nintendo an opportunity to create unique content for future generations they need to have quality 3rd party content on their consoles while they still make them. In order to do so, we need Nintendo fans to actually consume 3rd party content like the Playstation and Xbox counterparts.