Well yes - apart from the unsightliness of it, cabling laid across eg Concrete Pantiles without the benefit of being secured in several places, can, will and does abrade.
That leads to reduced life, either by causing electrical discontinuity or by allowing the ingress of water through damaged outer insulation. Capillary action then takes over and can creep very quickly along the cable, often as far as the Receiver input.
The poor practice of slinging cables willy-nilly over roofs is something that a competent Installer will avoid.
Sky, however, along with their sub-contractors, appear to have a time led imperative that precludes thought and care being brought to bear. And for nonsensical reasons (although they wrongly blame Health & Safety requirements) they don't like internal cable runs through roof spaces.