Management's role isn't necessarily to break unions but to keep workers compliant with company objectives. If the company is open to a union, they'll only impede it (and keep lower management out of the loop) so much so to make it a burden for workers to manage. If they're more offensive, they'll do what Apple, Trader Joe's, GM, Microsoft, Walmart and other conventional businesses do: take a complete about-face from whatever purported values the company is about and use their own legal prowess to weaken the constitutional rights workers have (it's only a crime if you're tried and sentenced when it comes to companies weakening unions).