Here in India (especially Kerala, the state I come from), doctors are pretty conservative. In fact the society is too.
I was asked not to be in gym or games for three full months (which I had to obey due to familial pressures as well) for apparently not much scientific reason.
I don't underestimate the capabilities of doctors, but most of them are damn too conservative. For instance, hardly anyone tries for a VBAC (vaginal birth after c-section) for deliveries as they find it too risky (yeah there is some 0.04% of ruptures to happen, which doesnt even mean death or major complications where the chances are even much much lesser); and I'm a victim of the same as my wife had to deliver the 2nd and 3rd as planned c-sections, just because she had the first one as c-section delivery.
In general, the society also are on the conservative side; as even now my friends and family cautions me about sweating it too hard at badminton courts and are always concerned about my food and weight and health and stuff. You can't simply blame the doctor; I would put the onus more on the culture.