It's not that the other Europeans particularly care about Ukraine. They remember what happened last time they tried to appease an aggressive, expansionist dictator. If Ukraine is allowed to fall then next it will be Moldova, Lithuania, Poland, and so on. Better to take the pain now while the problem is still manageable rather than letting the situation spiral out of control.
I generally agree but I go back to the pessimistic article that (humorously?) predicts Europeans will go back to living conditions from 200 years ago. I don't think rational European leaders will let that happen. It could be that they completely lost their minds (there are signs...) but I give them some more credit for now.
Even the Ukranians themselves probably have their limits on how much they care about Donbas and Crimea.
