@Jarkes
Like the thing is that the writers seemed to have take a lot of what people said should have happened to Starlight and then tried to package it all up into Cozy and to a lesser extent the same could be said about the whole of the season 8 finale trying to do this to the season 6 finale. But ok so here’s some of the more usual criticisms of Starlight that seems to have played out in Cozy
Starlight should have been a filly: And low and behold Cozy is said filly. This one is usually to try to say that Starlight’s overreactions and misgivings would have been more acceptable or believable if she were a filly over a grown mare.
Starlight best villainy was when she was a manipulator: Usually a critic that is basically saying Starlight’s mode of operation in The Cutie Map was much better than in Re-mark where she’s just OP. Here with Cozy she’s a master manipulator, able to pull a Mark Anthony on Neighsay, convince the school to follow her and lure the Mane 6 into a trap, and all without pulling a magic mcguffin out of her plot and keep it as her main threat she can use.
Starlight isn’t really good and is going to be revealed to be secretly evil still/she’ll betray everyone’s trust: So I know you dislike this one in particular, but then you know this one, that Starlight didn’t really get reformed and is just buying her time to strike back. And now look at what they did with Cozy, she infiltrates the school, get’s everyone’s trust and then betrays them.
They shouldn’t have redeemed Starlight/Too many redemption: So more a general one, but when Starlight first was redeemed in Remark, a lot were saying she should have been punished for what she did. Now here with Cozy she’s not redeemed.
Starlight should have been sent to hell: Following up on the last one, but what some were saying when the cast all just instant forgave Starlight, that she should have been locked up in Tartarus for her crimes against the space time continuum, and now Cozy just gets sent there.
No more OP unicorn villains!: So more of a broad one, but one kind of started more so by Starlight but probably the vagueous one but still a common complain is that it’s almost always a unicorn or super magically power villain, that at best Earth ponies and pegasus are minor antagonists. Well here the major threat is a Pegasus instead of a super magical being, and the reason I bet she’s a pegasus is so she can project better given that she can be at any height.