I’m going to go out on a limb here and make a blanket statement. Those who fail to place their chewed gum into a trash receptacle are also probably habitual litterers. This thought hit me on the weekend when I went to a nearby drive-thru ATM and noticed someone had placed a rather large wad of gum to the bottom right of the display area. Was that person not able to chew gum and make an ATM transaction at the same time?
The ire-inducing part of the whole spectacle was that there is a wastebasket less than a foot from the ATM as you drive away for people to place their receipts or any other kind of trash, INCLUDING WADS OF GUM. While I left no traces of my (electronic) deposit at the ATM, this person’s deposit was visible and will continue to be visible until some poor minimum-wage soul has to scrape off the remnants of whatever Random Inconsiderate Ass had left there.
Is it because it’s so adhesive that gum is the one acceptable item that people feel as though they don’t have to throw it away? It’s not like it’s biodegradable (at least not for quite sometime) so the remnants stay until someone removes them. A flattened out piece of gum on a city sidewalk can leave a dark mark for years. I’m sure there are pieces of gum in my high school that had been there for 20 years prior to me being there and are probably still there. You didn’t dare put your hand under the bottom side of a school desk since you knew the surface would feel like fossilized bubble-wrap from all the gum deposits made by the Future of America.
I’ve never been a gum litterbug but I do confess to one time in high school where Satan took control of my teenage body and made me do something that I now look back on with regret (albeit with some giggles thrown in for good measure). In one of my classes, there was a girl named Bethany who sat to my left and slightly in front of my desk. This angle took out her peripheral vision since she had one of those 1980’s style hairdos where all her hair was flopped over to the right side of her head. I had a stick of Juicy Fruit gum I was chewing at the time and I got the wicked idea that it would be amusing to take teeny tiny pieces of that very-sticky gum and start to flick it into her hair. Sure enough, by the end of class I had managed to make about 10 or 12 very small balls of gum from that one gumwad in my mouth and had created a buckshot pattern into her hair. As she finally went to put her fingers through her hair at some point, she came across the gum seeds I had planted via air mail and, needless to say, I laughed a bit more than she did at the time.
Man, teenage boys are dicks. 
Is the moral of my story that it’s ok to put your used gum in girls’ hair but not an ATM? No! But it illustrates the point on the temptation to put gum where it doesn’t belong, even from someone who never has really been a litterbug. Resist the urge, folks. A wastebasket is nearby, or at least a piece of paper you can wad up into to throw away later.