It's against the site rules here to suggest people haven't read the article - please don't do this.
I was replying to a parent comment which said 'how can anyone oppose a union'. Some people legitimately don't want to have to deal with a union, for any of many reasons. For example because the union supports political goals they don't agree with, or because the union favours other employees over them, or they just don't want to have to deal with two overlords, neither of which may be working to their benefit.
If they're asked and they say 'no thanks' then the union should just say 'ok thanks for letting us know' and leave them alone.
There's a weird attitude amongst unions that there is no possible way anyone could not want to be represented by them. That leads them to accuse any vote against them of being illegitimate.