Actually, there is a good answer to that. The answer is that Senate committee hearings are not, in fact, designed to help inform anyone of the facts important to the issue. They are prescripted performances to advance various agendas. No one learns, or is meant to learn, anything about the facts.
That may be the truth but Obama can't say it, any more than any other congresscitter can say it.
But it's also not why he didn't care enough to attend.
Darn it, my finger stuck.