I'm not going to go over the arguments about the offense caused by the presentation, but I think a point that's been largely missed is that using pornography as an analogy isn't just offensive to some, it's actually incorrect. So you both offend people by using it and fail to get your point across.
When you say that "X is like a porn-star" you are implying that X is faking it. So when you say that CouchDB performs like a porn-star you mean that it's phony.
If you need a people analogy for your tech product, you should probably go with athletes. They actually do perform well, make a large amount of money, get respect from a wide community, work hard to get where they are, have impressive physiques, etc.
Another porn analogy is something called 'geek porn'. Just a few minutes ago Tim O'Reilly retweeted:
via @paulsalazar: Geek porn-big data statistics on Greenplum at eBay. 6.5 petabytes. 50 terabytes/day. 96 nodes. http://bit.ly/O0Wya
I agree that that's a lot of data and that's it's very exciting (for a geek like me) to see inside eBay's datacenters and understand how much data they are handling. But is it porn?
Pornography's aim is to sexually excite the viewer. Are geeks sexually excited by the eBay data? I'm not (but I'm just one data point). But I do get a lot of pleasure from the eBay data.
And pleasure comes from many things that are non-sexual such as eating, listening to music, doing exercise, or achieving a goal.
So let's swap 'geek porn' for a 'geek feast'. I'm happy to feast my eyes on the eBay data. It fills me up with fascinating information and makes me hungry to be able to work on data sizes like that.
And finally the other problem with using the word 'porn' when there are viable, better alternatives is that there is the risk of offense. Many people are uncomfortable with pornography and don't want pornography analogies in professional work. Why risk offending people you are trying to communicate with?