I would say this is a little misleading. While I believe marijuana is not an effective way to treat acute pain after surgery for instance, I do believe it's effective in easing acute pain that occurs as symptom of certain diseases.
However there is one heartening aspect of these guidelines in that they treat pain as a parameter of healing and there is talk of tracking it as a vital sign on medical charts. It's a good start towards acknowledging that treating pain with opiates is not the extreme option it's made out to be by the prohibitionists.
[hat tip to Tim Meehan]