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.)
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.
Yes yes yes, a million times yes. This is so true for me. My (successful) attempts to modify myself to be more social were sparked off by meeting just such a person. It was a girl I met on the street three years ago. We started talking, then went to her place and spent the night talking. There was no sexual tension at all (though we did have sex much later), I just sat there ...
Followup to: Do you have High-Functioning Asperger's Syndrome?
LW reader Madbadger uses the metaphor of a GPU and a CPU in a desktop system to think about people with Asperger's Syndrome: general intelligence is like a CPU, being universal but only mediocre at any particular task, whereas the "social coprocessor" brainware in a Neurotypical brain is like a GPU: highly specialized but great at what it does. Neurotypical people are like computers with measly Pentium IV processors, but expensive Radeon HD 4890 GPUs. A High-functioning AS person is an Intel Core i7 Extreme Edition - with on-board graphics!
This analogy also covers the spectrum view of social/empathic abilities, you can think about having a weaker social coprocessor than average if you have some of the tendencies of AS but not others. You can even think of your score on the AQ Test as being like the Tom's Hardware Rating of your Coprocessor. (Lower numbers are better!).
If you lack that powerful social coprocessor, what can you do? Well, you'll have to run your social interactions "in software", i.e. explicitly reason through the complex human social game that most people play without ever really understanding. There are several tricks that a High-functioning AS person can use in this situation: