Why though? Companied invest in due diligence people and processes (unlike us plebs) If they get swindled, a fool and his money are soon parted. My intrigue is

Why though? Companied invest in due diligence people and processes (unlike us plebs) If they get swindled, a fool and his money are soon parted. My intrigue is that due dilligence is quite lax for certain types of people. I wonder what the criteria are. Surely 'those' academically excellent M&A people would never slack on a 100mil+ transaction, or so we are led to believe.