>>90920130There's a mix of two camps.
The valid complaint is that she gets an insane amount of work and exposure despite basically using the same two voices over and over again; it's frustrating to see her crowding out new talent when she's not very talented (compare to say, Billy West; he gets a shitload of work, but he's got the range for it). There's also the growing sentiment that she's just phoning it in more and more, coasting on her name recognition alone and trusting that her adoring fans will accept any half-assed work. Also, some people aren't fans of how she's acting like she's "The" voice of Harley Quinn, when at her best it was a 2 dollar imitation of Arleen Sorkin.
The less-valid complaint is basically that she's an attractive woman who won't fuck nerds that beat off to pictures of her tits, and because she voiced a pastel miniature horse.