Yes, I believe that in history, no one is specifically to blame. Alexandra did contribute to the Revolution primarily because she overly trusted Rasputin, and allowed hom to play a role in goverment to which he was not suited. Also, she gave Nicholas bad advice, partly inspired by Rasputin, and influenced Nicholas in a bad direction. She insisted on Autocracy, even though it was not a good poltical system for Russia anymore. She lacked the temprament to make her popular with the Russian people. Then and now, royalty fare better if they have charisma. This is not say that Alexandra did not have some, but she was not able to express it where she needed to, in public. So she seemed very foreign and unapproachable to Russia's common people.
But she did suffer with Alexei's illness, and also with her own physical ailments. She was not understood by very many people, and no likes to feel they do not have understanding with people. She was very much alone, and she knew it. She, too had to bear the difficult burden of Russian politics of the time. Her son's illness tore her apart, both emotionally, and physically. So you have to grant her understanding. But Nicholas played a role, too, as did many others. I can't relate to Alexandra much, except people may not have understood me sometimes.But we should all attempt to understand the challenges that were faced by the last romanovs.