All right, if it was honorable in the abstract to remain in the war, how would you - if you were the leader of Russia at that time - have ended it? You couldn't have said, "Okay! That's it, we're done fighting! War over!" No. You would have had to surrender, just as Lenin did, to extreme concessions. You would have abandoned all financial support from the Allies, and you would have been left with a country in even more disarray then it was already, which was - as we all know - a complete mess.
While the Bush/Nicholas II comparisons are tempting (their respective nation's early war jingoism, perhaps being the common theme between them) I think its ultimately apples and oranges. Nicholas, for instance, could read.