If I owned a company I wouldn't want to have a work force that just took a 50% pay cut. I'd rather just fire them all and start over as having a bunch of disgruntled employees would play hell on productivity
Not every employee that took a pay cut would take it out on the company by cutting productivity at an equal percentage to the wage reduction.
Even if your salary is cut by 50%, but you take it out on the company by cutting production by 20%, it's still a win for the company(which will eventually replace you with someone else since you're now being unproductive).
It costs money to train brand new workers.
It makes more sense to do the pay cut, and if there are any bad workers after that fact, fire them while keeping the good ones.
I also assume that management has already taken that into account in their calculations.
ex: Maybe they wanted to cut only 40%, but assumed employees will be disgruntled and produce less so they creamed an extra 10% on the top.