The problem is that the private sector faces the same pressures about the appearance of failure. Imagine if Boeing adopted the SpaceX approach now and started blowing up Starliner prototypes on a monthly basis to see what they could learn. How badly would that play in the press? How quickly would their stock price tank? How long would the people responsible for that direction be able to hold on to their jobs before the board forced them out in favor of somebody who'd take them back to the conservative approach?

Heck, even SpaceX got suddenly cagey about their first stage return attempts failing the moment they started offering stakes to outside investors, whereas previously they'd celebrated those attempts that didn't quite work. Look as well at how the press has reacted to Starship's failures, even though the program has been making progress from launch to launch at a much greater pace than Falcon did initially. The fact of the matter is that SpaceX's initial success-though-informative-failure approach only worked because it was bankrolled entirely by one weird dude with cubic dollars to burn and a personal willingness to accept those failures. That's not the case for many others.