Do people not open their windows anymore?

I don't know if it's because I lived in coastal SoCal for so long, where you didn't need to use heat or A/C and could just open the windows year-round, but now that I live on the East Coast, I open my windows at almost every opportunity. It's 51°F outside right now, but even with the windows open, it's a very comfy 70°F indoors, so I have them open.

Obviously, there are security concerns, so I don't leave certain windows open overnight, and I understand why some people keep them shut for security. I'm asking because I don't think I've ever seen a neighbor's house with their windows open.