what use of pan spittle..??

I have never understood the urge to spit pan and cough on the roads and walls of buildings and stairs etc. I actually dislike (hate) such acts. Seems govenrment should also provide spitting pan along roads, buildings and wherever possible.. but...
Anyhow, one funny incident to note here.. while walking down the road, I happened to spot a crow chewing from someones pan spittle :) funny to see. Didnt have a camera then to capture the image .. Atleast someones enjoying the organic waste.... enjoy..