I happened to read this article about recusal recently and I don't understand how some of these allegations wouldn't be explicit grounds for recusal, specifical

I happened to read this article about recusal recently and I don't understand how some of these allegations wouldn't be explicit grounds for recusal, specifically the son being a lawyer with a firm that tries cases in the father's court. https://popehat.com/2016/06/06/lawsplainer-when-must-federal-judges-recuse-themselves-anyway/ https://popehat.com/2016/06/06/lawsplainer-when-must-federal... Article is in the context of Trump, but you needn't let that turn you off.