Cathay (Bank) does not trust Taiwan documents

I just come back from the Cathay United Bank.

I wanted to open a bank account. The requirements are:
2 independent IDs, that is for foreigners: 1 passport and 1 Resident certificate.

for Taiwanese it is just 2 IDs, pick from:
driving licenses
National Health insurance
ID card

I wonder if that is legal to treat foreigners with PERMANENT resident different???

I als have a company in Taiwan, and asked if I could have a company account, but again, since I am the chairman, I must bring my passport and they want to COPY it.

Why do they need to copy a passport?
Why do they not accept the Taiwan ids ??? Do they not trust the own government who issue all these ids???

When I got my Permanent resident certificate, I was told that I have all the rights and obligations as Taiwanese, except politic rights (cannot vote, cannot be elected). Later one is not so important to me, since I am not a wrestler anyway.

they trust no oneā€¦