Well let's test this question in another way and see if it sounds dumb?
"Should Sony make Insomniac games only on PlayStation or continue to support Xbox now that MLB: The Show is on Xbox platforms?"
"Should Nintendo make Retro games only on Switch or continue to support Xbox and PlayStation now that they have Sony and MS mascots in Smash Bros.?"
It's a dumb question, but I only ever see it when it comes to Microsoft. One of the biggest criticisms with them last gen was lack of exclusives, so now they acquire a large publisher who has a stable of IP that can bolster that platform and the first thing people do is....essentially port-beg them to bring those games onto competitor ecosystems anyway?
Just weird to me; it's like do people actually want Microsoft to step up their performance this gen (where a lot of those criticizing have drilled over and over that exclusives matter) or was that just false sincerity? Because you can't really have it both ways, then suppose they do bring those games to a competitor ecosystem, and THEN turn around and criticize them about lack of exclusives considering you are
demanding they release their games on other competitor ecosystems in the first place!
It gets more annoying when I see some of these same people essentially use manipulation tactics, i.e they argue the value of exclusives for one ecosystem/system, see another system/ecosystem shoring up IP and games they value, so then they hamstring reasons why those games still need to come to their preferred platform and argue about such acquisitions being "anti-competitive" or monopolistic (even though they technically aren't and many companies do M&As all the time). Then in the chance those games still come to their preferred platform, they will attack the other anyway for lacking exclusives.
Now I'm sure games like ESO and Fallout '76 will still be multiplatform on Sony & Nintendo platforms, but I fail to see any genuine reasoning in people who swear that games like the next Fallout, Doom, Wolfenstein etc. must absolutely come to Sony & Nintendo platforms, considering there's no fair trade going on (i.e very few if any Sony/Nintendo games coming to Xbox and/or PC platforms). Even insisting games like Starfield and Indiana Jones "must" be multiplat tastes a bit of deception, considering the former would probably launch at a good time to ensure enough install base on Series platforms to keep it Xbox/PC exclusive, and the latter not falling outside the bounds of exclusivity (the older Indiana Jones game was a timed exclusive on OG Xbox, and the IP itself is smaller than Spiderman yet Sony now has two Spiderman exclusives to their ecosystem, both IPs practically wholly owned by Disney btw).
If it's all about profit for them, they will.
That's the case for ALL companies, but the disingenuous part is that almost no one ever asks this question WRT Sony or Nintendo's 1P output coming to other platforms. Again, these are all corporations, they just want to get as much money as they can, you would think Sony & Nintendo would know for sure they could get even more revenue and profit selling their games on Xbox and PC platforms, yet Sony barely does and Nintendo outright doesn't.
Do you guys think Sony and Nintendo are charities and want to leave money on the table? Or do you acknowledge that exclusives are important for a platform and if so, why insist that only one company (Microsoft) ignore what you consider a reality? I feel like a lot of people know the answers to these questions but have other reasons for insisting what THEY view as Microsoft's biggest IPs (particularly now, with acquisition of Zenimax) still come to other platforms, particularly PlayStation, and never once discuss about what games Sony should probably consider bringing to Xbox & PC to make the exchange fair (i.e it'd have to be a good bit more than MLB: The Show and Horizon).
And it's not worth saying that Sony and Microsoft's platform models are different; they both want to sell consoles, they have both spent tons of money in R&D and production for these systems, and they both still thrive off of software sales in their ecosystem. Microsoft's business model just has a few more additional levels of flexibility reliant on the cloud and subscription services, that's the only real difference. But it's certainly not enough for them to justify compromising their own ecosystem and services by bringing software that'd otherwise draw people to them as exclusive content, to other ecosystems wholesale such as PlayStation and Switch.