score:5
Several things to consider:
WW1 was mostly infantry war, and infantry suffered enormous casualties. Mutinies and dissatisfaction were common thing even in the West (French mutinies in 1917 for example) and poor Russian soldiers had even worse. Casualties were very high, they were often led by haughty but incompetent officers. Even more competent ones like Aleksey Brusilov usually considered Russian soldiers as expendable. Comparatively, Russian industry was less developed then let's say German or British, and only advantage they had was sheer size of the army. Thus, they often sacrificed soldiers for foggy strategic goals (like helping Western allies) people on the ground could not understand.
Russia proper was not endangered. WW1 was mostly fought in western parts of Russian Empire, present Baltic states, Poland, Ukraine etc ... This territory was not inhabited with Russian population. In fact, local population didn't care much which empire would rule over them. Common Russian soldier (unlike in WW2) didn't have the felling that he is defending Motherland, his family and home. After years of fighting they simply wanted all to end. Idea that Germans or Austrians could invade and occupy Russia looked very remote. Although Eastern front of WW1 was not as static as Western, fighting was still in trenches and by foot soldiers, and as witnessed by Brusilov offensive, advancing more then few hundred kilometers was simply impossible.
Agitation against the war was tremendous, especially by Bolsheviks who were actually brought and paid by the Germans to do just that. Of course, even February Revolution which brought Kerensky to power stemmed from the fact that population was deeply dissatisfied with war and misery it brought. In fact, unofficially, it was expected from Kerensky not to push to far - if he could not negotiate peace with Central Powers at least he was supposed to avoid huge loss of life, restricting himself to defense.
Overall, Kerensky offensive did look like huge gamble that (expectedly) didn't pay off. To his defense, it could be said that he didn't have much choice - his grip on power was slipping, Bolsheviks were already creating dual levers of power and would soon demand all power to (their) Soviets. He could not solve huge economic crisis (none could, but Bolsheviks were promising a lot) . Only thing that remained to him was to somehow gain support of the Army trough victory, at the same time gaining some respect from western Allies. Even without this offensive it is very likely Bolsheviks would strike against him at opportune time. Unfortunately, situation in the Army was such that mounting large scale strategic offensives was simply impossible.