First let me say that I like the Duff sisters, so I was not looking to hate this movie. In fact, we own Hilary's previous movies on DVD and I figured we'd eventually own this one too. Now that I've seen ("wasted money on" is another way to say it) this movie, I can tell you I will not ever buy this and will never watch this again.
The only reason I gave this a one instead of a two is that I genuinely like the Duff sisters. I was looking forward to a movie that my daughter would like and I would enjoy, if not just tolerate. I think the sisters should fire their agents, advisers, producers, or whoever put them up to this. It did nothing to enhance their careers. And I'm still not sure who they thought their audience is. Certainly no adults would (or should) choose to see this movie if they weren't going for their daughters, but neither was this movie properly aimed at young girls (the Duffs' main fan base.) As far as the PG rating, I am not a prude - I actually own Mean Girls, and I am fairly liberal about what my children watch (e.g., we love Friends, even though others think the material is not always appropriate for kids) but I squirmed in my seat for the moms that had younger children in the audience, as well as for my 11 year old daughter. Without going into detail - no spoilers - there were blatant references to adultery, gang banging, and sex that I did not think appropriate at all. There was some foul language. There was outright prejudice against all sorts of people. Referencing an earlier review, yes the comment was about "I Love Lucy" and not a Hispanic nanny, but nonetheless, annoying anyway.
Most importantly, the movie was mindless, and it didn't have to be. The Duff sisters aside, there were some genuinely talented people in the cast (Anjelica Huston, Maria Conchita Alonso) but the script was so bad that there was no saving this movie. There was a shot at redemption near the end, but the screenwriters blew that too. (How do these things even become movies?) It's almost as if the creators know that this movie won't last but a nano-second in history, as evidenced by the constant mainstream references and advertising plugs. Technically, there was bad continuity (Check out Hilary's hairstyles - in the beginning there is one scene where her french braid magically disappears with a camera angle change; or the lips moving out of sequence with the dialogue)and the jarring special effects editing were distracting and juvenile.
Like the characters themselves, this movie is all form with no substance.