As someone of a more libertarian bent myself, I find the opposition to unions slightly puzzling. It's clear the disdain is driven by opposition to socialism, as so many unions are subverted by socialists and their influence, but as a general idea they are perfectly acceptable if not ideal and should be championed - free association, individuals coming together to use their bargaining power to provide corrective balance to a part of the market suffering from power and information asymmetry… there's so many good things about unions.
In fact, if they were championed by - shall we call them economic liberals? - then they might be a damned sight harder to subvert and be a whole lot more effective and palatable. I know Sweden has strong unions and workers on boards (something I learnt from the very readable though still arguable book 23 Things They Don't Tell You About Capitalism[1]), with restricted power (the employees can never become a majority in any vote on the board) and it seems to me to be an obviously good idea.