It really is a matter of subjective experience and emotional connection (or lack thereof) to the characters and settings. I suppose you already know well enough why others that are tired of (or didn't like in the first place) crossover products, while for you you already made a different connection that sparks joy for you: that you had crossovers of your own already in mind, which I can only assume reached for forests over the individual trees so it didn't matter as much if specific characters seemed "off" as long as it worked for you to see them clash.

As a former enjoyer of both Smash Bros and Kingdom Hearts and even Super Robot Wars, I used to like crossover stuff but I burned out especially as the corporations got bigger and more bloated and devoured more and more of what were once unique entities, many of them not likely to ever be seen again except as crossover IP flexes by the ever-larger holding corporations. That's my take, and I'm not alone in it, I think.