OKCupid does interesting analyses of their user data. Here's a post looking at the impact of attractiveness on messaging rates (http://blog.okcupid.com/index.php/your-looks-and-online-dati...). Looks like, at least for their users, the "hot girl effect" is not real; the more attractive the girl, the lower the probability of a successful response.
The problem with OKCupid rejection is that rejection is not real.
You can easily spam out messages to all the hot girls and "rejection" is really a non-reply. Meaning that "rejection" is invisible.
In real life rejection means a "walk of shame" away from the girl, probably while your friends are watching, probably while they're laughing at you. OkCupid incorporates none of that.
While the graph does generally bare you out, one can see a few small turns on the OKcupid graph that might be a ghost of the "hot girl effect" - the most attractive female senders get more responses from guy of average appearance than from guys considered least the attractive...
You could also argue that when someone's already on OkCupid, they're already motivated to seek out someone and don't necessarily feel intimidated concerning who. This might be different than real life. But it might not be...
In my experience from a particular music scene, people with celebrity-level status who want to be treated like real people tend to be the people well worth talking to. Those who want to be treated like celebrities are generally less worthwhile to talk to.
Basically, you may not want to talk to anyone who's so shallow that fame is a really big deal to them.