Where I grew up, blood drive refreshment tables are generally staffed by little old ladies of the Episcopalian persuasion who have the volunteer ethos deeply ingrained. Sometimes they struggle with opening the water bottles, and it takes them a while to get the sticker off the roll, but they're sweet and earnest.
Today, a man refused the sticker.
Now, first, why refuse the sticker? All it does is tell people you gave blood, so if you're mildly woozy it's not because you're drunk or otherwise compromised. It may be a little cutesy, but that won't kill you. If you don't want to wear it all day, take it off when you leave the building.
Also, she's a nice little old lady! Why are you being rude to her? Jerk!