That's half of it. The other half is make people think they have a chance of pairing up but try to avoid them actually pairing up because, as Plenty of Fish once wrote in a blog post, it's not just that your users leave you, it's that they leave your service in pairs

Tinder side-stepped this issue when they changed to be a hookup site. The downside, of course, is you end up with a bunch of one-night stands instead of stable families producing babies.