My experience hasn't agreed with that. I definitely know people hook up like they would anywhere else. I definitely know that there are entire camps devoted to sex (i.e. Jiffy Lube) and so forth.
I'm curious if others have found the sexual aspect of Burning Man to be more predominant than that? Or do burners just come back and talk up the sex parts, leaving others with a skewed impression? For example, last year an ex-girlfriend seemed almost convinced that I was going to be tempted into having sex with someone there, despite my reassurances.
Remember that you're talking to someone who's very outside of that scene -- I'm not the sort of person who attracts much sexual interest at all (with rare exceptions anyway), so maybe I just don't see the parts that others do. It's not that I'm out hunting for a sexual experience. I'm just curious how others have seen it. No need for explicit details, share what you're comfortable sharing. :)