The reason you see mostly those kinds of couples (like a 1.80+ guy with a ~1.65 girl) is because there are way, way, way more of them then there are tall people. It's also confirmation bias; we see what we want to see / tunnel vision on.

The truth is most guys don't really care about a girl's height unless it's their own insecurity. Height is so low on our "priority" list, and even those who think they have preferences, in reality they set those aside in favour of more important traits/characteristics.

For me, height never mattered in a girl, but if she happens to be tall it's definitely a nice bonus. And I have a lot of friends who feel the same way.