Lenin and the "Old Bolsheviks", including Trotsky et al, were not the guys who did away with the Tsars. They did away with the guys who had done away with the Tsars just a few months before.

Then they pulled out from the war that was almost won and lost a huge chunk of territory and made one of the greatest European powers a joke. Which utterly destabilized Europe and led to the world's biggest slaughter two decades later.

Incidentally, it also was two decades later that Stalin finally had got rid of that Old Bolshevik scum.