I'm not ignoring things that don't fit what I'm saying I'm just saying that while Maya seems to be convinced the resets are to blame for Ami going crazy, she's also saying things (and past events also support) that indicate it's not JUST the resets that set her off. A thing that's been coming up more and more often recently is the implication that Maya's memories aren't any more trustworthy than anyone else's, and that despite her thinking she knows the way the world works better than anyone else she can be and has been wrong about things, if anything her confidence in her understanding of things tends to make her blind to certain things that others can see with a fresh perspective.
I didn't mean to imply that was the first thing Maya said, that was poorly worded on my part, I just meant she said that during the first part of her explanation. Basically what I'm getting at is that Maya's explanation is contradictory, so even if she explicitly says that the resets are the cause I don't necessarily believe her.
As for whether psycho Ami is a different person/entity, split personalities, or whatever, I'll freely admit I don't think I know anything for sure, but I do think that even if it's not the "real" Ami, I think it's the version of Ami that we've been interacting with for most of the game at this point, even when she's seemingly acting normal.
Nothing has actually indicated it's anything except the resets that triggered Ami though. You're just misinterpretating what Maya is saying by focusing on the middle of her explanation. It's only contradictory if you do that.
She's referring to Psycho Ami when she's talking about the violent and illusion stuff. Not Real Ami. It's why it comes after she already mentioned the trigger. It's also why she specifically notes knowing when they are is what changes Ami at the end. Everything that comes afterwards just makes the change grow.
As for Maya's memories, yeah it's reasonable to consider that what she thinks she knows is false. It's quite possible that Psycho Ami never actually did anything that Maya said she did, or even existed. That doesn't change what she's actually said though.
Also, it's possible we've ran into Psycho Ami before or at least glimpses of it. Personally, I think that Mangled/Happy/Memory Ami that shows up in resets is Psycho Ami's "true" form. However, the version that Maya refers to, seems to only occur when the resets are mentioned to Ami according to Maya. That version also seems to be completely uncaring, and even murderous towards Sensei. Meanwhile the Ami we know has done things like held Maya while she cried, and helped Makoto grieve. She's also optionally been rejected by Sensei, and hasn't killed him, so I doubt she's just been secretly Psycho Ami this whole time. Doesn't really fit the whole "dangerous" aspect that Maya tried to sell.
From here on out though, I can see Psycho Ami pretending to not be, well, Psycho.