While I would recommend A.O. Scott’s review and the recent episode of Radio Open Source to help you flesh out a little bit more the context for the film (though I don’t know how I feel about the accuracy Scott’s ‘conservative’ charge), I wanted to flag a quote from Inherent Vice that’s worth bearing in mind —
“Was it possible, that at every gathering — concert, peace rally, love-in, be-in, and freak-in, here, up north, back East, wherever — those dark crews had been busy all along reclaiming the music, the resistance to power, the sexual desire from epic to everyday, all they could sweep up, for the ancient forces of greed and fear?”
— as I feel it helps emphasize why Tarantino left Sharon Tate — and, therefore, per Joan Didion's logic, the 60's — alive.