Setting the "Mapping" node "Type" to "Point" means that the texture coordinate system is scaled so that the texture image keeps the same absolute size but "shrinks" relatively to the coordinate axes. That's why you see the counterintuitive behaviour of a shrinking texture on your object when setting a higher "Scale" value.
The "Type" setting "Texture" operates on the texture so that higher "Scale" values size up the texture on your object which is more intuitive.
