Why all the Spitting?

I go to the bathroom quite a bit, so that means I end up in public bathrooms quite a bit. Which brings up the following question?

Why do so many men insist on spitting (again and again) in the grossest and loudest manner possible?

Okay, you’re in the bathroom, but it’s a public bathroom so this doesn’t give you license to be as disgusting as possible. But time and time again I run across these guys, and have to resist the urge to scream. Are these just guys with bad smoker’s phlegm, or is it something else?