I don't think all of it is snobness but being in your own bubble sometimes. I may look at you and not even "see" you.

I'll greet (mostly a hi or head nod) sometimes. I'm so concentrated on where I'm looking that I don't see much of the scenery. haha BUT! It is very important for me to thank each driver, or cyclist that took the time to stop and let me cross the road or whatever. I do the same if someone is coming towards me through bike path where there is some sort of a gate (to prevent vehicules to get on path) and I know is faster than me and on top of this clipped. So I free him the way. Same when they come downhill to a tight spot. I give them the right of way if I'm going downhill and they have to go up. Common sense. And they thank you for this.

I try to treat others like I'd like to be treated.

But yes, there are some snobs and it's not because they have better stuff than you do. They are just like that.