It's interesting that you brought up high risk sports. The context of that quote was related to people injuring themselves by being too aggressive on stuff they should know better (one example was a relatively advanced practitioner pulling a calf muscle on a downward dog of all things). That's an example of a type of injury where the person sets goals (e.g. stretching to some specific previously achieved limit) without paying attention to the current state of the body (e.g. it's a fairly well known phenomenon that muscles are tighter in the morning than early evening, especially before warm ups).

Yoga isn't about quantified stretch goals, it's a daily fitness regime. So if you pull a leg muscle by going on a super deep downward dog first thing in the morning without warming up because you're aspiring to reach some guru-like level quickly, instead of seeing yoga as a fitness program to carry your body to old age, then yes, your understanding of the practice is wrong.