Yep, it is suppression, and praise the etiquette goddesses!
IMHO, some etiquette is archaic and a little silly, but basic "rules" about good manners and polite, civilized behavior are necessary for everyone venturing outside their cave to interact with others.
If you want to be "unsuppressed", feel free to do so in your own home, but out here amongst the rest of us, please suppress those base urges. In other words, pick your nose, scratch your genitals and expel gas privately, please. And thank you!