What’s polite in one culture isn’t in another.
If you came to my house I’m sure you’d do some things to offend me - wear your shoes inside, say something crude and offensive, but I’d try to just ignore it because I think it would be rude and embarrasing for both of us if I pointed it out.
It’s natural for people to be ethnocentric - to judge someone else’s culture based on their own… but sooner or later you’ve just have to get over it and realise that if you’re in another country and lots of people are doing something that seems impolite to you, then you are probably the odd one out who needs to change his attitude.
This is pretty basic stuff. Taiwanese people don’t need to be educated to your way of thinking, just like every country that’s ever been colonised didn’t need to be spared of their evil ways and be saved by Christianity.
I think I’ll go shoot myself in the brain.