I think it's the other way around.

Businesses see unions as enemies and transactions zero-sum. They view paying better wages and improving working conditions or providing actual benefits as a loss, rather than creating a "win" for the people who comprise the company.

Why is this? Probably because the investor class "matters" more than the employee class, through some odd inversion where the people who actually add value and make the company work are subject to those who don't.

Or, we could just cut the verbosity and call it like it is: Business don't want to deal with unions because of unchecked greed.