Huh. Excellent question.

I mean, this world is pretty exaggerated. Most lawkeeping institutions seem to be on their last legs. Maybe well-off high schoolers turning up dead is just something that happens all the time.

Mind you, if people did hate Morgan that much, I have to doubt her sister’s clowning would have been enough to save her.

Yeah, so far she’s…been rude about paying fifty bucks for a sticky bun, and been fed up (And a little controlling) with her clown of a sister while still being worried about her. (Though she didn’t deny the teacher blackmail. I’m curious about how far that went.)

She was clearly Not Great, but not so far gone that she’d get a shiv.

I think on of the reasons why we distrust Maggie more than Morgan is the fact that Maggie, as far as we know, genuinly wanted to become a Clown before her “death”. Morgan actually made fun of that, and then became one herself in memory of her Sister, so there defintely was some sort of Character growth from her side involved.
Arguably, we also only see that flashback through her eyes, so yes, she too is an unreliable narrator that might have made her own behaviour less harmful and/or romantisized the memory of her sister, thats very possible.
But the big thing is, we still have no clue what made Maggie go from the sassy little mischief-maker we saw in that old flashback to serial-terrorist. She went from wanting to be a Clown to trying to murder all of them, thats not something you do because your sister was mean to you. If this was all about getting back at Morgan, well, that would probably have started back before her death, and I highly doubt she planned EVERYTHING that happend since then, especially considering what she did to Ringmaster. No, there is still something we dont know, another, newer motivation, and given that this comic has already gone out of its way to mock the classic “we had a unspecified tragic event in our past so our atrocities against completely unrelated innocents are very justified actually!” argument I wonder what we might still be missing. Not to mention that we still dont know how/why she “died” and how she ended up with Ringmaster. There is agood chance that she is still to some degree suffering under his manipulations without being aware of it, convincing people of crazy shit was his whole thing.
Which just makes the whole thing more interesting, theres just so many details we still lack!

I think it’s because we haven’t seen Morgan doing anything in the flashbacks terrible enough that someone would have wanted to kill her. She comes across as arrogant and tactless, but not cruel.

The reactions of the people in the flashback seem very out of proportion with how we see her actually behaving.

We don’t have much insight into how Maggie reached this point. I personally doubt that faking her death was her own idea, or that she would have accepted it without brainwashing.