Milking tolerances to boost scores = cheating
The things we have control over, we want to be as uniform site-to-site as possible. Ropes, boats, courses, ramps, etc... the tolerance exists because people aren't perfect not so that we can milk them all to the easy side. Doesn't do anything for the things that are harder to control like wind, rollback, sun, rain, the rare turtle-to-ski collision, but that's why those are called things we can't control.