There's a lot of discussion about the varying ages of consent across different countries and questioning about whether that makes them have different views/standards of morality. I dont think it's that simple though. There probably isn't much difference between how people in the European countries being mentioned view the idea of a 28 year old sexually exploiting a 15 year old.
We all know that most kids start wanting to explore their sexuality before the age of 16, and broadly speaking, most people can understand a 14 year old getting up to stuff with someone of a similar age. We have laws that make it illegal for two 14 year olds to sleep with each other even though I dont think as a society most of us are morally outraged by it. It's how you protect young people who might be sexually active but still young enough to be vulnerable to predatory behaviour that's in question. Obviously it complicates things a little to say its ok at 14 but only if the person is close to your age so for the sake of simplicity there's an argument for having a slightly older cut off at 16. I dont think the morality behind those laws is actually that different, it's more a case of how each country thinks its best to achieve clarity in the law without needlessly criminalising kids but at the same time protecting them.