If I remember correctly, those senate rules were changed for very good reasons. Namely, the Republicans--who seem to place much greater emphasis (and value) on judicial appointees than Democrats--were blocking Obama's nominees to all levels of the judiciary in a manner that was totally unprecendented. So the only option the Democrats could see was to change the rules, to start getting some of those long open vacancies filled.
A lot of this "change in decorum" is primarily because of Mitch McConnell. He apparently still feels greatly aggreived by what happened to Robert Bork when he was nominated to the Supreme Court by Reagan back in the 1980's. Up to that time, there was a pretty strong tradition of one party confirming the nominees of the other party. And when the Democrats went against that tradition, McConnell apparently vowed to get his revenge some day.
Which begs the question, why did the Democrats feel they just couldn't approve Bork's nomination. I think they had some concerns about his views on abortion, but my understanding is the primary reason(s) had to do with their anger towards him surrounding his role in the Saturday night massacre which occured during the investion into Richard Nixon. Here's a snippet from this
LINK:
"On October 20, 1973, in an unprecedented show of executive power, Nixon ordered Attorney General Elliot Richardson and Deputy Attorney General William Ruckelshaus to fire Cox, but both men refused and resigned their posts in protest.
The role of attorney general then fell to Solicitor General Robert Bork, who reluctantly complied with Nixon's request and dismissed Cox. Less than a half hour later, the White House dispatched FBI agents to close off the offices of the Special Prosecutor, Attorney General and Deputy Attorney General."
So there you go, the toxicity of Richard Nixon's presidency spilling over into today's extremely toxic environment surrounding judicial nominees. Cause and effect; karma playing out on the national stage.