Yeah, what put her on the map as a kid was too silly/childish and simply doesn't work for an adult female. She didn't have an adult sense of humor like Wiig, Fey, etc. and as a result no longer had an audience for her own headline starring films. That's why she was tagging along in supporting roles in Hairspray and Easy A. Supposedly she was dying to get a raunchy part in Hall Pass in order to make a transition to that style of humor. I think she also could have wound up typecast in films as "the token girlfriend" (a role Sarah Silverman hated). So, I can understand why she lost passion for it.
I'm not sure it would even be okay to make fun of her considering she may actually be mentally ill. Although at times I'm left wondering if she just wants to be like the Kardashians, etc. and much of this is on purpose. It's kind of fascinating and I'm dying to know what actually going on with her.
I'm no psychologist, but I would diagnose Bynes with severe narcissism. She wanted to be the next Gilda Radner but never put her money where her mouth is. Given her downward spiral, I can't really make fun of her either.