I can't comment for other sites - but until the law changed, that's because (at least us) worked our bollocks off for hours (and still do when we can) to take the sting out of things and find a resolution that suited so it never got that far.
But I gave two examples, one footy related, that was off the top of my head. I know I'll find more and refresh myself if I delve into my note book but I can't be arsed.
Tis why when we give a polite public nudge (as others can attest to, I usually do it via PM when it's a one off posting), we want it to be listened to - not questioned as we're doing a favour for members who might not know the law on this front.
It doesn't have to end up in court to cost you time and money and most don't - but they cost time and money (and worry!) and it's not worth it for the sake of keeping some thoughts in your own head.