Basically what Vartha said, that some critics won't think she's serious enough. Especially as a female character, there seems to be the mindset that every female hero as to be like "grrrrr, I am so serious and empowered, because I am fighting gender stereotypes, grrrr." This Mantis is like a kooky, dippy starchild, and I think it's wonderful. I want to see her in the Avengers so she can interact with characters like the Hulk, Widow and Hawkeye. The insulting nickname Tony Stark will come up for her will be next level.