My sense is that he's said what he's going to say about his family and feels that there's no need to bring further attention to them.
Concerns about ethics tend to be episodic, and those episodes are stimulated when there are horror strikes. And, of course, Tennessee Waltz was a real horror story.
They all want to differentiate themselves in positive ways.
Suppose you're on some committee - say the Transportation Committee, and a major transportation reauthorization bill is in the works. If you're managing the bill, you're going to make sure that the speaker's, majority leader's and whip's districts are treated pretty well.