While I agree with your sentiments and morality, there is a level above the one you you quote, where there is money to be earned.
There is no point being idealistic about, " not working for a penny less than £




? " and not working, just as kidding yourself that every job MUST be fully vacuumed / presprays are timed to the second / wanding is done, as it was taught, even in areas of virtually no soiling and so on.
In every business there are rules and guidelines, pedantic fools follow the book to the letter and get paranoid when presented with a challenge which their book does'nt cover.
Practical, confident individuals just " get on with it "and collect the money, which allows the realist to manage their time more effectively and even while working on a lower rate, will, because they are more efficient, earn more money.
They would be foolish to work for £20 an hour, when working efficiently, they will earn £50 to £70 per hour, by being good at managing.