It wasn't perfect, and it was mostly carried by the performances. The script rang completely hollow and false in spots, and tried way too hard to be quirky-cool in others. It won the Academy Award for Best Original Screenplay. I don't remember the other scripts it was up against, but I don't recall feeling any particular outrage at that victory because the end result was a pretty enjoyable movie.
That script and its Academy Award victory launched Diablo (I've heard her real name but I don't remember and don't care) Cody's career as a screenwriter. Now she has a TV show ("The United States of Tara") and a regular column in Entertainment Weekly magazine, and she's written a new movie (Jennifer's Body). She's gone from stripping for dollars to rubbing elbows with Spielberg.
You've heard at least a precis of Cody's story; she was a stripper ('coming up on the main stage, three songs with...Diablo!") and then turned to writing, wrote the script for Juno, sold it, and starting turning up on Oprah and elsewhere; suddenly a small but vocal contingent soured on her because she got too popular and started sniping at her work on Ain't It Cool News and other web hangouts for the malcontent.
Like I said, I thought Juno was pretty good. I had some problems with the script, or at least the version of it that made it to the screen, but it had some heart and wit and told an engaging story. I think I read the dialogue get praised somewhere for its realism, but it wasn't real at all - it was an idealized reality, a shiny sparkling hyperreal image buffed up by Diablo Cody, with bits that rang sort of true and bits that clanged off of the truth like a basketball flung from half-court clangs off of the rim. But that's OK. It was fiction. It's no crime for fiction to reflect the truth as the writer sees it; that's actually fiction's entire job.
I haven't seen Jennifer's Body yet, but I don't think I'll have much of a chance because the box office isn't good. Early reports indicate it boasts that same wink-wink, nudge-nudge self-aware "reality" in its dialogue that Juno did.
Predictably enough, the same malcontents are all over this one, ripping the carcass to shreds, shouting "I told you so" at the underwhelming box office.
That's what you do when someone gets too popular: you pull the knives out.
Now I happen to believe that the majority of this backlash is simple jealousy. I don't know if Diablo Cody is a great writer; time will tell, I guess. I don't personally think Academy Awards necessarily attend greatness -- the list of great scripts that haven't won awards is far longer than the list of those that have.
But Diablo Cody, at least, had the discipline to sit down and create something. I don't know what breaks she got along the way, but success is usually only a product of some hard work and opportunity. Sometimes it's a 50-50 split between those two elements; sometimes it's 80-20 for hard work, and sometimes it's the other way.
But work has got to be part of it. Sooner or later, if you want the success, you've got to get off of your ass and do something. If you don't, the only thing you can do is take bitter potshots at those who did.