Re: So...
It's perfectly reasonable that everyone who gets paid £X should pay the same amount of tax, whether they are a contractor or permanent employee.
It's perfectly reasonable for contractors to demand higher pay from their employer in exchange for the lack of benefits and the job insecurity. The employer gets the benefit of not paying for sick/holiday/etc and being able to fire easily, so the employer can and should pay for it.
It's not reasonable to expect other taxpayers to pay more so the contractor can be pay less tax. The taxpayers don't get the benefits of the contract.
Of course, the way this should have been done was to fix the tax system properly, perhaps by taxing dividends as income (with an allowance for any corporation tax already paid). IR35 is an abomination of a law - it's a kludge, it's unfair, it's overcomplicated, and it's unpredictable.