I don't think it is just people choosing to display all the badges, I think flyertalk seems to be putting them there automatically for some reason. I'm not sure what logic is being used to determine the number of countries visited. I haven't selected any badges at all, nor do I wish to, yet it is displaying 10, 20 and 30 countries for me. I certainly haven't been to 30 countries and I doubt I have been to 20.
Interesting. Mine was blank other than "15 years as member". I then manually chose "40 countries" as my personal count and added the badge. Didn't know some had these badges added as default.