Hi Dog Mother
I don't know where that information came from - it's not something I have heard about.
With regard to your PIP, the DWP generally wants evidence from medical professionals. Being turned down for a driving licence a long time ago does not give them any up-to-date evidence of your current medical condition. However, if you're leaving the house, the DWP will want to know how you do it - and obviously, you are unable to drive yourself -so you can tell them you don't have a licence, and then they will focus on what you do (walk, travel by bus, take taxis, not leave home, driven by someone else etc). They will be more interested in what you do than being unable to drive - so I'm not sure it gives you any additional advantage. One of the other mods will correct me if I'm wrong.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems