Your BIL is right, if he considers Tiger’s despicable behavior to be none of his business, then it’s none of his business. But we all get to make that decision for ourselves, and I for one will not support sponsors who throw that kind of guy a huge chunk of coin.
I really do think that who he sleeps with, or doesn’t sleep with is any of the publics business. Granted; he is multi million dollar golfer, leader, and a lot of people look up to him. We still shouldn’t pass judgement on him for his actions that so many of us humans do. We should not hold his sex life against his ability to play golf. Everyone makes mistakes and has fallacies. I know Tiger to be a good man, his father was an ex-Special Forces operator, and Tiger has done several clinics for veterans and their families.