Speculation, but probably their legal department feels like that'd be a sort of implied warranty, and if the route wasn't appreciably safer (what does that even mean? Surely reasonable people/people with a different set of strengths & weaknesses will differ), they might open themselves up to lawsuits?
Possibly a similar situation if they claim they can tell one route is safer than another, but then don't give you the safer option?
Possibly a similar situation if they claim they can tell one route is safer than another, but then don't give you the safer option?