The problem with Scarlet is not with her existence, but the way she was brought into existence in the game. It is implausible for a character of her “genius” and almost infinite resources to be unheard of in the game. If npcs mentioned her in outside of the living story before she appeared to give her some credence, we won’t feel so violated and our intelligence insulted as a player.
For example she was a very accomplished sylvari in the asuran colleges and her ideas went against the Arcane Council…it would have been more interesting if this was made mention during the Asura personal story. To add to that, the Order of Whispers as well as the Durmand Priory had absolutely no knowledge of her when she seems to have so much influence over the other lesser races, and her research into chaos/elder dragon magic.
Because she just appears out of nowhere with all this sudden power and is linked to almost everything that is happening now leads people to believe that she wasn’t really planned as part of the main story and is more of a bandaid antagonist. Scarlet is also very arbitrary, she could have been a magical sentient omnomberry and it still wouldn’t change the current lore about her. And worst of all, this is what Anet is trying to pass off as a congruent storyline, as if the players don’t know any better.