Because the Founding Fathers wanted the government understaffed

I don't know that I have anything new to say on the absurdity of Peter Diamond's nomination to the Federal Reserve's Board of Governors being held up, but I'd just observe that this is the everyday price of the Senate's dysfunctions and inanity. Big stuff like health-care reform either gets passed or obstructed in full view of the entire country. But endless small stuff, like nominations to the Federal Reserve's Board of Governors, gets held up or never gets done because so much time is being wasted on obstruction and there's little public pressure for the Senate to do the stuff that nobody knows it needs to do in the first place.

To make this a bit sharper, a lot of Republicans have been arguing that the filibuster is terrific because it keeps the Senate from doing big, unpopular things. But the reality is that there are time-consuming ways to get around filibusters (like the reconciliation process) and so the big stuff that the majority party's base cares about actually does tend to get done, and health care is a good example of it. The problem is all the stuff that the public doesn't know enough about to have any opinion on s getting held up, and in many cases, simply abandoned, as the majority party wants to do legislation the electorate cares about as opposed to spending time on nominations they've never heard of.

The analogy I like to use is to a really sick person. They may be able to muster the will to keep paying rent, turn in their big report to their boss, and so forth. But a lot of little things in their life will go undone because they don't have the energy left over to complete them. And those things add up.