Here is where the benefits of promoting exercise far outweigh any risks that people who exercise may experience. There is no need to hedge here. Exercise might not cure your depression or even help it, but in general, exercise has been shown over and over again to be one of the most effective things that you can do for mental and physical health.

I can't really agree with this, there are definitely lots of negative avenues from exercise if not done right.

Generally, hopefully, most people will do exercise more or less "right", but this is not a safe assumption.

That could be said of almost any healthy thing.