Originally posted by Nephthys
As I recall critics were very generous with the prequels. No-one really called it out as outright trash until a while.
You recollection is only partly correct.
Many early reviews came in bashing the film. To the point where it was almost a "fact" the movie was bad before it was even released. I specifically remember the film being talked about on the news where at the end the news presenter stated "It's a pity early reviews are suggesting the film isn't that good."
However you're right as well. Many people who gave TPM a positive review at the time have since miraculously done a complete U-Turn.
No Star Wars film to date has gotten across the board positive reviews though. TFA will be the first. I'm calling it now. I called it a long time ago. Because no Lucas now. There was just too much animosity towards poor George.