Do as the Romans?

One thing I raise my brows about these days while watching MLB(大リーグ) is something that are incessantly spat out from players mouths. Every time TV closes up a player, manager, coach, whoever, all of them without an exception are munching something, punctuated by busy spitting. In the bullpen, batter box, waiting circle, on the infield outfield, as though they do not care where they are.
From what I heard, it used to be a chewing gum to relax themselves. Imagine the ground is spotted all over with spewed chewing gums. It's not something you want to see. As is to be expected, they seem to get aware of the sticky sole of their spikes and they changed their pacifier from chewing gum to sunflower seeds which are obviously healthier and suitable for athletes.
Still, you might not want to imagine the ground in a ball park covered with a mixture of saliva, possibly occasional sputum, hull, in which they sometimes wallow at an exiting moment of, for instance, a slugger sliding into the home plate kicking up a cloud of the soil which actually is the compound of bodily liquids.
In contrast, how clean Japanese baseball players are. They are just sitting on the bench absorbed in the game. All that comes out of their mouths is cheer or words of abuse if at all, not the liquids.
Valentain, the manager of Chiba Lotte Marines, is famous for his balloon blown from his bubble gum. In front of him is a bucket so that he can spit whatever he wants to in it. Yes Japan allows him to chew but never to spit it around.
The other day I was very shocked to see Matsuzaka was doing exactly like other brow-raising Americans do. I have never heard of an announcer or commentator refer to this when this is absolutely what we do not want children to mimic, while they never fail to criticize fist fights over, for example, a hit by pitch(デッドボール) which I find fascinating and even educational to kids in a sense teaching them that they have to fight when they have to fight.
A proverb goes when in Rome do as the Romans do. But mucus spitting is one thing I would not want you to do even if all the Romans were doing it.