Someone who has exclusively trained calisthenics isn't going to be magically able to lift two times his own body weight, simply because your body and muscles will get used to training with the same load and strength gains will simply plateau. Someone who has specifically trained to get stronger by using an increasing load is going to be able to lift more than his own bodyweight.
Stop trying to sell one thing as the cure, denouncing everything else. Ultimately the most important thing is that people just do any kind of exercise. People should do what they like best - be it calisthenics, weightlifting or even powerwalking. Naturally, one approach might be objectively better for your health than another in the long run, but that doesn't matter if the alternative is not doing any exercise at all.