I cannot honestly work out what would drive a person to do something so completely disgusting.
I will point out that over here in the UK, I recently saw a notice on a bus, which stated:
"We carry DNA testing kits on these buses. If you spit at the driver, we can retain your DNA and hand it to the Police. This is assault".
Why on Earth would someone spit on anyone else, bus driver or whatever? Normal human beings simply do not act in that way. It is beyond my comprehension why we need notices on buses reminding people this is wrong.
Sadly, there are people around who think this sort of behaviour is not only acceptable, but a reasonable course of action to something they consider "annoying".
Personally, if anyone spat in my face I would step back, issue them with a look of complete contempt and then walk away from that person with dignity intact. I wouldn't give them the satisfaction of responding.
If it were a "friend" of mine who did it, I would remove that person from my life, if it were an enemy I would make sure to avoid them for all eternity and if it were a stranger, I would not wish to embark on any kind of conversation. Whatever, I would not allow that person to make any particular difference in my life.
I am a believer in karma. What goes around, comes around.
Peace and love, mote it be xxx