I don't think anyone is arguing that no-one should make an effort to make themselves visible... the concern lies with transferring responsibility from the 'hitters' to the 'hittees'.
Driver hits something at night... but it's not the drivers fault because who/whatever they hit wasn't illuminated or reflective enough.
where Adrain said "an insurer has already tried to get a pedestrian's damages reduced because they were not wearing hi-viz." ... would you (@
Linford) say the insurer is right in this case? If the answer is 'yes'... then the next case may well be "the pedestrian wasn't wearing enough hi-viz, and it's still partially their fault they were hit."
Like i say... we're not arguing against taking responsibility for ones own visibility... it's about shifting the blame from those with ultimate responsibility, that being the 'hitter'.