Actually, they have said that marijuana is good enough for pain relief from playing. And, they also said that the opiates that they are given for pain are actually more harmful to their bodies than cannabis.
And, I can attest to the pain relief properties of marijuana. My roomie uses it for pain relief because she doesn't want to take any of the painkillers that the doctor prescribes her. Seems that when she takes a prescription med, she ends up constipated. Doesn't happen when she smokes.
Oh I've heard all about it... I'm just not so sure about the idea that it isn't addictive. See Josh Gordan, Ricky Williams, and Nate Diaz.
Marijuana is not physically addictive. You can stop smoking it and your body will not have any kind of withdrawl from stopping. And, I can attest to that particular little thing, because before CO went recreational, buying in my area was seasonal, and there were times that you couldn't find any for a couple of weeks. When the dry times came and I ran out, I simply just waited until it became available again. And no, I didn't have any withdrawl from it.
I've also talked to quite a few veterans up in CO (I always am wearing a US Navy Retired ballcap and vets come up and talk with me), who have said that when they came back from the ME, the VA had them on a regimen of 10 to 15 pills PER DAY for various things like PTSD and the like. Well, when CO went recreational, they decided to see if it could help with their problems, and guess what? It did, and they dropped from 10 to 15 pills per day to just one or two, and were healthier because they weren't experiencing all the side effects of the other medications. Opiates make you constipated by the way.
And yeah, you could say that people can become mentally addicted to marijuana, but you can become mentally addicted to ANYTHING, from people (it's called codependency), to gambling, to shopping, to exercise, to food, etc.