Why are conservatives so opposed to public-sector employees bargaining collectively for salary and benefits deals? Two reasons:
One: unionization distorts the labor market by introducing extortion into the negotiations. By threatening the company with shutdowns, the union can drive up wages and benefits up to absurd levels, far past what that labor market would otherwise bear. Contrary to popular liberal dogma, employees are nothing more than tools the board of directors and managers use to make as big a profit as possible for the stockholders. They are no more important than the machines on the factory floor....probably less valuable when you think about it.
Two: unionized public employees essentially negotiate with politicians for salary and benefit deals. Neither has a stake in the money over which they wrangle. They are negotiating with other peoples' money. Democrat politicians give unions sweetheart employment deals, and in return the unions literally re-elect and then bribe those politicians with union dues. It's an incestuous circle of corruption and the taxpayers are forced to fund it all, without a say so.