Some gringos do the same. It reminds me of the students in college that kept 5 or 6 ski lift tickets wired to the zippers of their parkas that they always wore to the bar to advertise their athletic prowess.
Some people like to prove they are 'old timers' and 10 marbetes mean theyve been around. .
Either that or they can't afford a razor blade to scrape it.
Probably never empty and clean ash trays either.