I would technically say that in general bodybuilding is healthy. It's the AAS, diuretics, etc., that make it unhealthy. But in it's purest form, it is very healthy.
And of course I agree that being 300lbs is unhealthy. I don't think there is any question about it, other than some guys trying to play mental gymnastics to try and justify it to themselves. And then once you're 300lbs you're trying to justify eating 500 - 600 grams of protein for your size.
Many years back I fell into the whole ridiculous high protein diet phase thinking I needed 2 grams per body pound to keep my gains going. So sitting at 200lbs I was eating 400 grams of protein, and the reality is that it did absolutely nothing but give me diarrhea and feel like crap. Cut my protein down to about 250 grams and replaced the extra calories with carbs and fat and felt amazing. Just having gone through the experience a few times, I strongly believe that overeating protein is a real thing in bodybuilding that people don't seem to think will affect their health, when in reality, I think it definitely does, especially when we're talking about the kidneys and using AAS on top.