
Honestly I think it’s a subconscious dominance thing. Like how dogs pee on things to mark it as theirs. Guys spit on shit as a show of like yeah I did that, it’s mine nos, are you intimidated? At least the men I knew who did that shit, it was definitely on par with their behavior in every other aspect.
I would say two reasons. Either they have allergies so snot is constant right now, especially if they have bad allergies. Or they have chew and spit because of that, though the latter is more common in rural areas. I personally don’t spit snot out but completely understand people who do, as it is a quick way to clear your nose without a tissue.