These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Base Breaker: While Avenger-Fans have largely forgiven her for her actions during Disassembled/House of M, for most parts of the X-Fandom she is still The Scrappy, also because she never got any real punishment while Cyclops (whose actions also happened under a mental breakdown and possession) gets hunted down like a criminal.
Canon Sue: She was sometimes suspected of being this for the writer-artist team of Kurt Busiek and George Perez, who increased her powers to unheard-of levels, had her save the day in a lot of stories, made her deputy leader of the team, and let her, not any of the top-tier heroes, have the last word in JLA-Avengers.
The popularity of those two storylines, along with her absence from the comics between 2005 and 2011, means that it's common for readers to think of her as an omnipotent Reality Warper, even though her powers don't work that way anywhere except Disassembled and House of M, and both those stories have since been explained away as the result of an outside source amping up her powers.
The Woobie: While she's done some questionable things, it's pretty hard not to feel bad for her.