She had a unique perspective on films - and that is always interesting.
However, as her years in Hollywood show, she fell victim to the same thing most critics do: wanting to make movies themselves. Warren Beatty actually saw through that and got her on his side for a while by bringing her on board of many projects (that did not work out in the end, hah, surprise...). Her love for Brian de Palma also exposed her as someone of questionable intentions (praising those who showered her with affection, hating those who did not cater to her).
In the end, critics like her had too big of an ego. They became stars themselves. And that got in the way of their work.
On the other end of the spectrum, today, you have someone like Harry Knowles who absolutely loves those films he gets invited to watch the shooting of. But he hates those he gets the cold shoulder from.