But I don't see why I'm supposed to enjoy it

Because people can tell when you don't, even if they're too polite to mention it.

That's why, btw, "How To Win Friends And Influence People" advises cultivating a genuine interest in people, and PUAs advise more or less the same thing. By becoming a connoisseur of the finer (in the sense of more finely-graded) distinctions between people, and cultivating your curiosity about "what people are like", you gain more enjoyment.

And genuinely enjoying a person's company is the hardest, most expensive signal to fake... which might be why people evolved to value it so much.

I know a couple who embody this principle, btw -- Garin and Vanessa Bader. I met them at a series of marketing workshops, actually. By their second time there, practically everybody would line up to talk to them during breaks. Not because they were presenters or anything, but just because they radiated such enjoyment to everyone they spoke with, that people could hardly help but want to spend more time with them.

The way Vanessa explained it to me, when I interviewed her for one of my own CD products, was that people are so constantly worried about what other people are going to think of them, that they no longer even notice. But the moment they encounter someone who genuinely accepts them as they are, without any judgment, they suddenly feel so much better that they can't help but want to be around you. So, she said, she and Garin just always acknowledge and accept everyone.

And that is the difference between these very charismatic (and fairly successful) people, and people who go around judging whether other people are living up to their standards. ;-)

(Fair disclaimer: I don't claim to have personally reached anything remotely near G&V's level of nonjudgmental acceptance, but I can definitely see why it'd be a good thing for me to aspire to. And I've occasionally attempted to practice it in specific situations, with some small success.)