Every sovereign country has a right to block companies based on their security risk assessment. In this case however, the given reasons sound a bit flaky. Would have almost been better if they gave no reason at all.
So why don't you look into it and make your opinion from the facts?
https://www.washingtonpost.com/opinions/2018/12/18/chinas-in...
https://www.nytimes.com/2018/11/22/world/asia/taiwan-electio...