I know the union types like to take this position, but it just isn't valid or possible. Essentially you're saying "Could you imagine what management would do to us if we had a union negotiate a contract, and then that union disbanded over night leaving us to face the consequences?"

Without a union, PCL would not have had that last contract and we probably wouldn't be having this discussion. Is that to say the pay/compensation would have been worse? Who knows. Maybe the threat of unionization would be enough to keep the pay/benefits acceptable enough to keep a union off property. Maybe management would go the route of your JO scenario, get super greedy, and force an Eastern Airlines redux.

But "...management would have probably gone for more if they were non-union since they wouldn't need a judge's permission to cut their pay and work rules." is trying to oversimplify it.