People are different from each other. For some people, sex is very important. For others, not so much. The “not so much” people are likely to see sex as overrated, because they’re comparing their experiences with what they hear from the “very important” people. Given how much we hear about how great sex is, it’s unlikely that anyone considers it underrated.
People engage in sex not because they’ve heard it’s great, but because they have sex drives, because the act itself is pleasurable, and because they value the things that go along with it (such as intimacy). Most people don’t engage in it because of how it’s rated. It’s not like trying the hot new restaurant that everyone is raving about.
Like any activity, what are you putting into it? Are you doing it, if you bother at all, just to get it over with? Or are you able to give yourself over fully to your animal mind yet enhanced by tantric awareness and control over your physical and mental energies? Your results will vary accordingly.
To paraphrase, “Sex is like pizza; when its good, its really good. When its bad, its still pretty good. Except prison pizza, that stuff is effing awful.”
Yeah I think that’s the key to why it isn’t at all comparable to the great majority of other under/overrated debates. Those are usually about things people choose from among, or choose to do or not, where they at least think it’s wholly their conscious selves deciding. Few people I think are deluded enough to think that their rational selves are mainly in charge when it comes to sex.