It's really not even primarily the privately-held corporations that are the problem. Some family business, even if it's big, is more likely to care about its reputation because that's their family's company and it's still going to be their family's company in 50 years or more.
Whereas you get publicly-traded companies and the primary shareholders are investment funds, whose managers get bonuses based on short-term results and who may not be in the same job or having the fund hold the same companies in as little as a year from now. So their incentive is to have companies squeeze customers for short-term gains and then choose the right time to pawn the shares off on some bag holders who see strong recent numbers and don't realize what that strategy does to the company's long-term prospects.
It's basically the further removed those benefiting financially are from the actual operation the more likely the business will care about money over everything else. The public private distinction matters less - private companies can still have external investors calling the shots.
Whereas you get publicly-traded companies and the primary shareholders are investment funds, whose managers get bonuses based on short-term results and who may not be in the same job or having the fund hold the same companies in as little as a year from now. So their incentive is to have companies squeeze customers for short-term gains and then choose the right time to pawn the shares off on some bag holders who see strong recent numbers and don't realize what that strategy does to the company's long-term prospects.