The New York Times asks this very sensible question in this article to be published in the Sunday NYT magazine. The answer to the question might seem obvious - the people who fear Khodorkovsky are the same people who imprisoned him. Putin & Co.
Perhaps another question might be so obvious. Namely - "What does it matter?"
In my opinion, it matters quite a lot. I don't have strong feelings about Khodorkovsky the man. I've never met him. From what I've read, he is a man of strong will & character - who followed a familiar path toward amassing his billions of dollars. In other words - he used connections & some unscrupulous means to get his fortune started. All the oligarchs did.
He differed from the rest, however, in that he tried to stay & fight Putin & Co. Obviously, he badly misjudged his foes.
All this matters for Khodorkovsky, obviously, as he sits in his prison cell. But might not be so obvious is how it matters for Russia. As long as he sits in jail, we cannot possibly talk about the rule of law in Russia. We cannot talk about a level playing field for doing business. All this matters for Russia because without a functioning legal system and a predictable environment for investors, economic development in Russia will continue to be quite shallow. The country can continue to live off its oil and gas revenues, but this is not a growth strategy. If Russia is going to develop economically and politically, Khodorkovsky must be freed.