If you care about the image of the sport and maintaining its popularity, then it is your business. You can't have the #1 player in the world doing this if you want the sport to thrive, what kind of message is he sending. Publicly, it's inexcusable. Privately, I have nothing against what you said but it's a damn question mark about what he thinks is humorous in life.
I don't find it funny, either and agree that Janko should've known it can be controversial for someone.
Then again, some love to do silly/crazy things with their friends, and Nole is one of them. You may have your opinion on whether it was careless of him(Janko) to put that pic in public, but definitely not about the fact that Nole took that sort of picture with his friends privately. Make sure that it was Janko who posted it on the net. Do you know what was Nole's thoughts on this issue?
As for the last part, I don't care about your taste in humor at all. But what you said in the previous post was about how Nole should/shouldn't spend his time with his friends in general.