I used to think this line of thinking was a bit elitist¹, but I find that I also get a bit depressed by people who simply don't look up at birds. It could just be a lack of eyesight, but I find even with people great eyesight, just wont look up, and I perceive it as a general lack of any curiosity about the world around them.

1: and it is elitist to a degree, if you believe these people will never develop the interest. I live in the knowledge that they will, and that we're all late bloomers in some certain respect.

I was once standing at a bus stop when I heard the sound of a large radial engine. Looked up to see a Lockheed Constellation flying overhead! Not a single other person standing at the bus stop or walking past looked up.