I understand that there is always an attachment factor, which isn't necessarily a bad thing; it just shows how much people like those characters.
The old models looked good from certain angles, but they had many serious problems that I had to conceal in various ways because they were impossible to fix in HS2. For example, there's a reason why none of the female characters have their eye-to-ear area uncovered by hair, and the side view shots of their faces is almost non-existent. And it's a scarry reason.
I just hope that you and others will eventually accept the new models when they're fully completed.
As for development time, I'm not creating every model from scratch; I create a base high resolution model and a low resolution model that can be easily edited. Alongside good UV mapping (which allocates texture space for each part of the character), I can create different models with only minor adjustments to the high resolution model. I transfer details to the low resolution model and use a Substance Painter preset I created for the textures to make visual changes. It's a relatively easy process.
The thing about Mirai renders were meant as a joke to imply that her new model looks better, but it seems the joke is not that good if I need to explain it.
Persona 3 Reload is an amazing remake!
It's nice to have some good games once in a while, and since these two months will be full of them, I need to manage my time more carefully.
P.S.: I never imagined Mirai would become so popular... what a monster I have created!