Most of the Persona 4/5 fans get excited when a new Megaten game comes out, but start complaining when they get their hands on the game. Most of the vocal fans of those two games really only care about the waifu/life sim part. So when you get rid of that, you get rid of the sole reason they care about the game. They rarely acknowledge the battle system, the fusion, or even the dungeons. It’s kind of why Fire Emblem Three Houses blew up, and how many fans of that game also refuse to play any other Fire Emblem game? They’re not Persona style dating sims, why bother?
There’s quite a few Megaten games on the 3DS, and outside of the handful that care about Persona Q (and only the first one), the P4/5 fans don’t acknowledge that ANY of them exist. It’s a fandom that really only cares about 2 games, with a small handful that acknowledge the third game exists, but that’s been shrinking over time.