I know older men in comedy who can barely feed and clean themselves, and they still work. The women, though, they're all "crazy." I have a suspicion--and hear me out, because this is a rough one--that the definition of "crazy" is a woman who keeps talking even after no one wants to fuck her anymore.
The only person I can think of who has escaped the "crazy" moniker is Betty White, which, obviously, is because people still want to have sex with her.
Not being familiar with the entertainment industry, I'll take her word for it, and no wonder she's angry if she sees that routinely. What interests me here is the complaint treated as comedy, softened by the self-deprecating clause in the middle, and bordered by the joke about Betty White, which reads as an abrupt tonal shift. There's a current of genuine frustration running through this essay, of the same strain that underlies her character, Liz Lemon, on "30 Rock."