I've been giving OKCupid a go recently as well. I don't think I should complain about it.
Thus far, I've interacted with a few women there and they were pretty interesting exchanges. Nothing ended in a date, but hey... I'm not there just for the sake of dating. I'm cool meeting new people there as well. But dating is probably why I'm there primarily; making new friends, sure thing.
That said, I've been on a few other sites and I found they were n-times worse than OKCupid. At least even a free account on OKC gives you some stuff to work with, compared to sites that don't even give you to option to send a message to someone if you think they're interesting.
I'm not looking for someone on the spectrum specifically, even though I know that an NT in most cases will not result in something fruitful. Those are my personal experiences and dating history. But who knows; I've been having a blast interacting with a few ladies I met online on various sites without dropping AS, so perhaps there is hope that some are totally cool with me just being me.
As others pointed out, the problem isn't OKCupid, it's dating sites in general. The things you describe are things I hear about any of these dating websites; people saying they're not interested, the type of people there being bland and not interesting enough. Perhaps you also just cater to the wrong crowd. Or just look at the wrong people.
It's quite interesting in that I've been active on a dating website, a dutch one, that profiles itself as a website for people more into alternative stuff (alternative music and such), yet on OKCupid I've found way more women with whom I had shared interests, that go beyond music, but even delve into stuff like being into the same comics, writers, movies and the list goes on. So for that I can't really complain how OKCupid is a terrible website. The same can be said about Plentyoffish; found a few lovely ladies there. Though a few other of these datingsites, they just show me the most bland women whom I could never see myself get with; to me those are the type of women good for a one night stand, something I'm not looking for at all anyway.
But given I've been single for not even 3 months, I'm just trying to test the waters a bit first. See what people are looking for and chat with people first. I'll see how it goes down. It also means I haven't been awfully active to arrange dates. Right now I'm not that interested in dating I guess; unless perhaps, the right person shows up.