It's my belief that this happens because sources giving exercise advice to the general public want it to be as safe as possible because they don't know if a robust 20 year old who plays football is reading it or a middle-age desk jockey who has never done a pushup in their life, etc....
That's why I think they should just educate more and refer to in-person coaches more often. Also, imo it's not that difficult to just say things along the lines of "if you've never done this before, you should always start lighter/less-intense than you think, and very gradually increase load/difficulty."
I wrote about it in another thread, but given that there is evidence that people can have "damage" and no pain, OR pain and no damage, I think it's best not to nocebo folks out of training. If you feel fine doing it, carry on. Just don't go nuts. If uneducated people read/hear "don't do X or else you will break your back," they might expect pain if they ever move away from "neutral." That creates avoidant behavior, which is the opposite of increasing capability.
I think as long as people feel okay, whatever gets them training more is good. I read some trainers on social media saying as much; a movement doesn't have to look perfect before you can load it. In fact, just getting people working towards getting stronger, faster, etc increases their confidence and motivation to train more, and better.