Unionization - a root cause
A root cause of unionization efforts is the poor treatment of employees. This poor treatment can take many forms from illegal hiring and promotion policies (excessively blatant favoritism of some type), hideous work life balance, unreasonable work loads, harassment of employees whose views do not toe the party completely, etc. not just pay, benefits, or work place safety. Obviously the list is not exhaustive. If a company is facing constant unionization efforts the mismanglement should be wondering what they are doing wrong. But given the mismanglement is often less competent and clueless than the run-of-the-mill PHB nothing will occur.
I am wary of unions in general but if forced by mismanglement I would consider joining one depending on my options at a that time. And this is being played out in many companies, highly paid professional level staff are fed up with mistreatment and do not see that grass is greener elsewhere.