I'm not arguing they aren't.....just at the idea that PSR is somehow there to ensure clubs are 'sustainable'.

Even the three year rolling model its based on is bullshit. All businesses invest from time to time in order to move from one level up to another, some of it cna be done over a short period, but some larger projects take 5 years plus to build into the model. So you are restraining multi-million pound businesses with ambitious owners to achieving those ambitions over three years in a very risky environment when a five or even ten year model would be better.