This became a standard excuse for why no one is losing their job over the HealthCare.gov debacle: Firing any of the appointees in charge would just trigger a disastrous confirmation process that would lead the agency rudderless and chaotic for months and possibly for the rest of Obama's term.
Simultaneously, the rules change makes it far easier to hire new people. The confirmation process had become so difficult and, because of that, the vetting process so intense that top prospects routinely turn down presidential entreaties. Christopher Hill, who served as the ambassador to Iraq, described it vividly:
"Today, any nominee to a position requiring Senate confirmation can expect to spend many hours listing past places of residence, attaching tax returns, detailing family members' campaign contributions, and answering questions about the employment of domestic help or gardening services and whether such employees were legal, tax-paying U.S. residents. The vetting process will even go back to one's teenage years all to ensure that anything that the Senate's own investigators can find is known before the nomination is formally submitted.
"During my career, the Senate confirmed me five times. Each time, the vetting essentially started from scratch. In addition to the countless forms, lengthy questionnaires, and background investigations, there was an interview with a paralegal whose job was to ferret out any information that might conceivably bear on the nomination."
Among other things, the process effectively ruled out anyone who had ever done or said anything interesting. Blandness, rather than brilliance, became the dominant virtue.
After all that, the nominee would often have to put their life on hold for months or years as the Senate worked through the obstruction and, sometimes, the nomination would end in defeat. Republicans filibustered the nomination of Nobel Prize-winning economist Peter Diamond to the Federal Reserve Board for over a year. Eventually, he just gave up, and so the U.S. government lost the service of one of the world's most brilliant economists.
Thursday's rules change makes situations like Diamond's far less likely. It makes it easier for the government to hire good people, and makes it easier for them to fire bad people.