Why was it confiscated? Because political messages aren't allowed at the Olympics.
Why is it political? Because China does not recognize Taiwan's independence, and holds much influence over the games. Taiwan competes under the name of Chinese Taipei at the Olympics, and beat China for the gold in doubles Badminton.
It's not about thin skin or weakness. The point is to show China's power, to force international agencies to bow down. They did. The message was sent and received.
It's "political" in the sense that it involves politics. I think you mean to say that it isn't "controversial" outside of China, but I would still disagree. A lot of countries are more influenced by China than Americans and Western Europeans, and are reluctant to use the name Taiwan or imply they are an independent nation.
Then the name china can't appear on apparel either it being just as political in reference to the same situation.
They only compete as Chinese Taipei because China has leaned on the commission to not recognize their nation even while self governed. It's the UK telling Canada they can't have Canadian merchandise and have to compete under their Commonwealth name.
That might be a rule. I know I've seen people waving flags, but I don't remember seeing a lot of signs. Maybe?
But it wouldn't have mattered if someone had written the word Taiwan on a postcard; if they were holding it up during the games, it would have been confiscated.
No, I was in the arena (not in this session but in others) and the size was definitely not a problem. There were people with bedsheets that they wrote stuff on without anyone confiscating them.