Because when it comes to online dating your profile is your entire identity and how could someone really get to know you through a 1000 character count bio. Its not that efficient. Girls get tons of messages per day. They need to filter out who is worth talking too and who isn't, so for one, if you're attractive that will help a lot. Second, you need to stand out from the rest of the crowd, put in effort. Its all a numbers game in online dating. Are you going to be unique or be another number.
I seriously think it's the website format... the way it's set out. The endless list of results. Getting dates with decent looking girls off okcupid isn't hard. Tinder is a little more challenging with how flaky girls are, but doable.
POF? Wasteland of whales and single mothers and girls who don't want to date, lmao.