I think there needs to be a massive review of all tax laws. Instead of starting from a place where this money earned by method A is liable for Y tax and so on, it should start from the premise that all money is taxed at X rate (where X rises when it reaches the next threshold).
Then you could have a system of exceptions: the first £12,000 of wages, money paid in pension contributions up to a certain amount, interest from ISAs/national savings, the first £350k of the estate of someone who's died etc. The onus would be on the company/individual to show that the exception applied, rather than on HMRC to show that the money was liable to tax.
DP's ex has her own business. It's run from a room in her house, she has one (very part-time) member of staff and negligible expenses. The last year they were together (approx 12 years ago), the business turned over £180k. She paid tax on what she paid herself as a salary, around £28k pa gross. The remainder, after expenses, was treated as a "dividend", but instead of paying the dividend to herself, she "lent" it to her company. Then, as the company repaid the "loan", it was tax free, because loan repayments aren't taxable.
Almost all her wining and dining (and there's a lot of it, especially "wining"), her car and related expenses, a chunk of her household bills and so on goes through the business so that it's offset against the corporation tax.
Her business? She's a tax consultant. 
She reduced her "salary" massively a couple of years after they split up, so that she was eligible for working tax credit and their son would be eligible for help with fees at uni, or some such. Which is just taking the piss, imo.