I don't understand why people think he hasn't been straight forward. What more do they want him to do or say? He's issued statements, he's had press conferences, his doctors have had press conferences, they've shown diagrams describing exactly what his problems are. Medicine isn't an exact science unless it's something obvious like a broken limb where the bone is sticking out of the skin. When it's a situation like Rafa's knee, the inflammation and years of built up scar tissue would make it doubly difficult to immediately diagnose why this pain was caused by something different than his usual pain but they've kept the public and the media informed all along the way.
I do agree with you that in any case, Rafa is not obligated to share his medical information with anybody. Nobody got their knickers in a knot when Roger pulled out of tournaments last year to 'rest his groin' nor did they demand pictures and doctor's reports. On the other hand, it shows how popular Rafa is and how important he is to the tennis world that after so many months and so many important tournaments and newsworthy events, he's getting more attention than almost anyone else.
This rest and healing period is going to do wonders for him both physically and mentally and I have no doubt he's going to be back next year better than ever.