It's easy to quit after you had a hit series that ran its course a little longer than it should have and you've made a **** ton of money. I like her quite a bit as an actress and have for a very long time (before Weeds), but if she's going to quit then just do it. This dramatic temper tantrum is unnecessary. It is like the people who "quit" websites. Just stop going … just stop acting.
The entertainment industry has been ridiculous for decades. Nowadays with social media and the ability to get information on celebrities nearly real-time, information is just shoved in our faces, even if we don't care about it. Some celebrities are nearly as guilty as the folks talking about them.
She's not wrong though on her thoughts about people unleashing attacks on celebrities. It is a sport for some. Go to any site what posts photos of celebrities doing random (and normal) things. Read through the comments left by people who are probably 500 pounds and living in their parent's home. People will call her (among similarly sized actresses) fat and ugly. They'll just write and write without consequence. As an actress, she has to ignore these things though. It's just how people are.
If she wants to live a private life then it will be difficult in some respects, but it can be done.