People don't get it. It's just PARODY
This is parody, done in the style of many of the Hollywood blockbusters I'm sure you adore, from the 30s, 40s, 50s. This is kitsh, tacky, overacted and all the nasty things you say of it, because that's the way it's suposed to be.
This film is the life of a romance novel writer in the early XX, a character with as many birds in her head as you can stuff in there, a selfish, cruel, childish woman who had a bright imagination which she poured in her books, and was very successful in a morbid way. Pure celebrity, just like what we see today, but with more bling.
There's nothing to argue about. This is not supposed to be serious, thoughtful stuff. Just get over it and enjoy it, if you want to, or don't watch it. Simple.