It's like picking your nose in private. You can raise a stink in public about how you'd never do it with fake disgust, but I'm sure you do it.
I don't think it's any less weird to meet up in person with someone after just seeing 3-5 pictures of them and a vapid bio. Looking at the Facebook profile can give you a sense of how they conduct themselves and whether they're crazy. Like if their wall is dedicated to some MLM scheme and they get in fights with their friends/family. Or whether their Tinder pictures are from 5 years and 100 lbs ago.
If you think it's weird, then I'm not convinced you've used Tinder enough to escalate it into a date. If you did, you'd know that having one mutual friend in common makes it easy to hunt them down and even if you don't, Tinder gives you enough info to anyways unless they have their privacy settings jacked up.
