I can only speak for myself, but I would not rule out a SP because she also advertises on LL. I do not check LL for providers but also do no not use it to cross-reference. I doubt that many would do.Yeah it makes me want to never advertise on it anymore because I'm worried it makes me lose credibility.
I think you can almost assess it in a vacuum i.e. do you get enough good clients coming from that page vs. time wasters? Is the revenue generated through LL worth the trouble of advertising there.