Unfortunately, if you haven't been to Europe/Brazil and aren't a football fan, you won't understand at all.
Sports is actually one of the most superstitious fields around. Some players will absolutely refuse to wash the socks they wore during a winning match. Some have "rituals" that they adhere to more religiously than religion itself. Fans are, if not just as bad, even worse.
Put it this way: How do you feel about antis booking up whole blocks of tickets for concerts, only to boo and jeer continuously throughout, attempting to demoralise the girls? When T-ara turned up and gave their performance in those outfits, it was the equivalent of being the cheerleading team for the other side.
So sadly I'm not going to blame the football fans this time, and instead put it down to a disastrous mishandling of T-ara by management who couldn't be bothered to oversee all these (major) details. They just push the girls into any event they think will increase publicity, and don't give a sh*t about anything else. I mean, has everybody missed the fact that our girls were rushing around ALL DAY in those tight, PVC-ish, non-breathable, obviously uncomfortable outfits?
Let's place the blame where it belongs, people - not on the footie fans, but on management whose bottom line is money, not the girls' wellbeing or image or the feelings of the potential audience.