Blame our capitalist set up.
Thing is, it's just much easier to measure financial 'worth' in the private sector, particularly in consultancy type jobs where you're selling business the whole time.
For example, I've worked with colleagues who have personally brought in ten million pounds worth of business for a company. That will have been all their own doing, with very little support. That provides jobs for others, keeps the company afloat, pays lots of tax.
It's understandable that the company wants to pay them a damn sight more than £250,000. To keep them and keep that revenue in the company. Otherwise they'll go elsewhere and do the same for someone else.
In that sense, they're 'worth it'. However, we don't have the same easy straightforward measures to measure the 'worth' of public sector workers. And that's where the problem lies.
Houseful talking about worthiness and nobility is neither here nor there. We live in a capitalist society. We sign up to the social contract. People like the super salesman are hugely important, because they generate lots of revenue for the exchequer, which then goes towards paying for the doctors and nurses and teachers that do those noble and worthy jobs. If we lived under a socialist regime, it would be totally different.