He didn't only keep it, he reinstated it after Grassley killed it the first time.
If they can't accept the new order now, after everything that Republicans have done, then Democrats deserve to be bamboozled on judicial nominations. It couldn't be any more obvious that Republicans simply don't care to play by the old rules any longer, and any attempt by Democrats to keep that going is only going to be a handicap on their time in power and another rule to throw out when Republicans have their time.
This isn't just about playing by the rules. This is about dumbness if they want to give GOP the power to hold up everything, knowing they are radical extremists & obstructionists. And knowing that GOP when it power will steamroll everything on a party line basis.
GOP will keep pushing extreme right wing stuff while the Dems will try & play for the middle. In the end, the GOP drags the middle so far right that actual centrists are termed as radical extremists. Dems just sit, push rightwards & allow the GOP to drag the compass to the right.