From what I heard so far the problem seems to be that sites trying to make it more comfortable for users (like giving them actual guidelines) get often warning

From what I heard so far the problem seems to be that sites trying to make it more comfortable for users (like giving them actual guidelines) get often warning letters from lawyers. And not many projects want to risk legal battles. At least that's the way here in germany, but I suppose it's not much different in the US.