Answer: They get around the pesky will of the majority of the American people.
Here's a lovely post from the DailyKos praising the president of the AFL-CIO for encouraging the president of the United States to appoint officials during a recess in order to get around the Senate.
We've grown used to hearing "progressives" urge Obama to make laws with signing statements and executive orders. The treaty he's using to occupy Iraq never went to the Senate for ratification. His list of Americans to assassinate was never authorized by Congress. The Fourth Amendment and habeas corpus are not as dearly treasured as people pretended they were when doing so could make a Republican president look bad. But recess appointments is a new one.
When it comes to unconstitutional senate rules like the filibuster, progressives and the president consider them sacrosanct. It's far more important not to question a rule that lets senators representing 11 percent of Americans block all legislation than it is to pass any of the horrendously bad bills under consideration. One must uphold the rules, be principled, fight fair with "the other side." The other side is, of course, one of the two parties, even if both parties are opposing the will of the people.
But when it comes to a president, rather than Congress, rules are for pussies. Democratic party loyalists, just like those on "the other side" have a different attitude toward abuses of power when it is a president abusing power rather than congress. That this results in both "sides" year after year shifting more and more power to presidents is not a concern for either "side". So, when Bush appointed John Bolton during a recess to get around the Senate, that was a horrible thing to do, not because it set a dangerous precedent (it set a good one apparently) and not because Bolton's policies would mean massive death and suffering (what does that have to do with winning elections?) but because Bush did it. If Obama had done it (and who at this point would dare assert that Obama won't appoint Bolton to something?) well, then it would have been fine.
Now, the Senate is an institution that almost always opposes the will of the American people. Appointments are blocked by single senators and other maneuvers that are anti-majoritarian even within the hideously corrupt institution of the Senate. Obama could appoint someone to office that Americans would approve of in a referendum, but that at least a few millionaire rednecks in the Senate would never allow. But the president is already LESS accountable to the American people than are senators. The solution here is to improve the Senate, not worsen the presidency.
Anyone failing to fight for the removal of the filibuster rule can shut up immediately about the will of the majority. If we don't want individual senators blocking appointments or bills, then change the rules and don't allow that. If we want Senators to follow the will of the people and overcome the corruption of money, media, and party, then we need to establish clean elections, undo corporate personhood, end the doctrine of bribery as "free speech," create independent media, and at the very least set an example by not ourselves obeying the antidemocratic orders of party leadership.
We can't do these things, you say? Then what is the point of having given the Democratic Party what they do not admit they have: complete power?
Recess appointments? Really? This will fix soulless, spineless, sell-outs? And nothing worse will come of it?
If looking to the distant future is too difficult, just ask yourself this: Would you want President Sarah Palin making recess appointments? Proceed accordingly.