"As long as is not an adult dude (like, the body and mind of an adult) wanting to date a minor, then I think it's fine."
People say that because the law says that it's bad and they don't want to be seen as a creep by defending large age-gap relationships with obviously immature children.
That being said, the same people who will claim that it's evil are usually the same people who don't have a problem with underage kids dating/sleeping together and they often find it impossible to explain why it's suddenly morally OK when both people are underage as opposed to only one of them.
I personally don't think it's OK for minors to date/sleep together and I find it far worse than large age gap relationships since at least one person in an age gap relationship will be able to fully take responsibility for the outcome (i.e. kids, finances, etc...).
