The overwhelming majority of people would benefit from doing resistance training 3x a week, cardio 3x a week, and shifting their diet towards more protein and less carbs and fat. People who fall outside of the large majority due to specific medical conditions need to understand their medical conditions and how they impact their daily life, because expecting everyone else to always take into account these issues is unreasonable and unproductive.
To be frank, this is a dumb point. The morbidly obese person probably can’t even run for 30 seconds. It won’t destroy their joints for the rest of their life. Suggesting activity over inactivity is good advice for basically every human alive.
Suggesting activity is good, yes, but suggesting someone should start with lifting specifically when they have issues with their joints without any further context is moronic.