First, "non-zero" is an extremely high bar, especially for mere "contribution". Knowing that there is non-zero contribution tells us nothing about whether it's

First, "non-zero" is an extremely high bar, especially for mere "contribution". Knowing that there is non-zero contribution tells us nothing about whether it's a problem we should care about. Second, there is massive survivorship bias (well, actually the literal opposite, I suppose) going on here. There is a massive bias towards hearing about the deals that go bad. There is little effort to chronicle the times this worked out well, and a LBO saved a sick company.