well they should be seen as american. thats the system. most people see them as american i would say. those that don't are completely in the wrong.
could you get away with calling them an outsider? that they will never be an american , they will never understand the culture even if they speak english fluently or were born there? would that be a widely accepted view in the states? not a chance in hell. but this is the attitude of 99% of Taiwanese when it comes to foreigners here.
why do some people accept different standards here than they would back home? i can accept it(because its reality), but i don't think its right and i don't like the term wai guo ren. it means outsider, its not formal or polite. just call me a laowai or adoga and say what you mean. i am ok with that. now if i had a kid here and they were called a wai guo ren throughout their life here that is something i wouldn't be happy with.