WHY would someone need to earn more than £50 million a year? This seems a reasonable question. “They don’t,” seems a reasonable answer. I certainly can’t think of any other answer but I have a 10-year-old car and original model iPhone so I’m perhaps not the right person to be speculating as to what someone would do with 1,805 times the annual Scottish salary of £27,700.

Jeremy Corbyn asked this question this week; presumably he asked it rhetorically. He asked it while being interviewed about his announcement that Labour would introduce a wage cap. The high-earning horses startled. So too did those who don’t now and will never earn the huge sums Mr Corbyn’s suggested wage cap would affect.

Although he did initially mention a nationwide wage cap during television interviews on Tuesday morning, he officially proposed the less wide-reaching policy of a cap for executives at companies with government contracts. This would affect a pay ratio at these firms where the executives could earn no more than 20 times the wage of their lowest paid worker.

The suggestion was ridiculed from the Right and Left despite excessive executive pay being an issue even the Institute of Directors has acknowledged is a problem. Here’s my theory: truly progressive ideals will never be welcomed by the majority because humans are self-preserving; even those with the best of intentions, who give of their time and even claim to be the most left-wing and progressive.

Left-wing policy can be a bit daunting: more tax, less money. It’s hard to take people with you when all you’re offering in return is the greater good, rather than a right-wing promise of unfettered riches. Most of us suspect we will never earn upwards of £50,000 a year, never mind £50m a year, and yet we want to know that the option’s there.

Similarly, those who purport to be on the Left know that inheritance perpetuates inequality. But they are still happy to pass on inheritance and to accept inheritance.

They know that mortgage deposits from the bank of Mum and Dad help perpetuate inequality but they still hand over lump sums to their offspring because they don’t want their children to be the ones who miss out. They don’t want their children to suffer for the sake of their ideals, even though the “suffering” in question is a few more years of renting or a starter flat rather than going straight into a family home.

Few are going to will their estate to charity or make their children stand on their own two feet unless it’s legislated for, which will never happen because there’s no appetite from either side.

Generally, people have aspirations to more than they have. Left-wing policies put limits on aspiration that will not affect the majority but which frighten the majority: first they came for the £500,000 a year salary; what’s next?

There’s nothing particularly attractive about left-wing ideals if you’re already comfortable. It’s a hard sell, making personal sacrifices for the wider good, even when you’re aware it’s right. It’s partly the success of the SNP. People can take comfort from being on the apparent side of progress without taking a financial hit.

It makes it easy for those on the Left to blame others for not doing enough to fight the good fight and to be self-congratulatory about their own decency. Inequality will never be rectified without bold moves but it seems unlikely the electorate will be bold enough to take them.