The government needs to function; to function correctly, just like a business, it must also be staffed.
Regardless of the political affiliations of the President once a nominee is presented to Congress, it is the Congress who then needs to take action. Action deferred/delayed is action not taken.
This action does not take away from the power of Congress to Advise and Consent - it simply ensures that Congress actually accomplishes it's role or accepts the continuation of government if it fails to act.