I think that would produce a lot of false positives, and therefore a lot of disappointment for physically unattractive people. Some people aren't particularly motivated to pick only 9s & 10s; most people accept people in their own range or higher; and sure, some people who are 6s end up happy with 2s. But "We're really hitting it off!" followed by "Um, oh, sorry, I just remembered I left a pot on the stove BYE" is much worse than just not getting any "likes" at all.