It's not fud. I hurt my back several times because I didn't realise I didn't have sufficient flexibility to do these lifts safely. Now years later, hardly a week goes by that I don't see people doing these lifts badly.
Your answer is a bit like the old joke: "Patient: doctor it hurts when I do this. Doctor: well, then don't do that".
The reality is that while these are great exercises, they are exercises that are easy to do badly, and that lot of people do badly without anyone ever pointing it out to them, because they think they know them and don't ask for help, and often people don't realize what the warning signs are.
To point out that there are risks with these exercises is sensible, and not FUD, because you can seriously harm both your back and your knees with them if you don't make sure you learn them properly, and a lot of people start out with insufficient flexibility to be able to do them properly.
I've done heavy compound lifts for 15+ years now, and my knees and back are stronger than they ever were before I lifted, but I also did manage to hurt my back when I first started, because I thought I'd learned how to do it properly but hadn't, and nobody corrected me, and I lacked the flexibility to even have a chance of doing them correctly. Thankfully I didn't hurt myself seriously, and took the opportunity to actually sort out the problems, but not everyone gets that lucky.