It's literally because her damage scaling is the worst in the game bar none combined with the fact that her super pushes you AND stuns you AND her lowest damage is still more than capable of taking down those with range but no health. She's not designed to be a fucking tank killer as the devs claim she's designed to be a Scrub carrier and for room temperature brainlets who aren't capable of a playstyle other than Shoot, Shoot More, *Dash, and then a Mega shot into more shots. It's absolutely mindless and takes no effort whatsoever. People don't rage as much as they do with Amber when it comes to her because novelty for one, but also because the character is so fundamentally broken that everyone who used to be seething now just doesn't give a shit because the only strategy with her is to AVOID ALTOGETHER. But don't take my word for it.