I find that they can be helpful.
They actually help with my SI issue.
Okay, I know that doesn't sound like it makes sense, but it's because they give much more awareness of what my lower body is doing so my form improves.
And better form usually means a lower chance of getting hurt.
I save them for only my heaviest sets, but if I was having difficulty beyond the heaviest sets, I would wear them for those too.
Unless someone is very competitive and pushing themselves towards their true limits, I typically see people getting hurt when either form is off and/or unbalanced programming is present.