Russia had been fighting war for a very long time which lead to suffering and made the people tired of war. The provisional Government could not put an to food and fuel shortage as result of the war. The Russians developed hatred towards the provisional government because it did nothing to end the war, instead it put in place death squads to hunt down and kill deserters. They never took any step towards solving the land problem.
All three governments wanted to be superior and they did act that way. But soon, it caused many issues. This is probably not the best answer but I hope it kind of helps :)
