It's economic wishful thinking which ignores the the benefits that taxation brings in providing services, from utilities to health, to everyone, thus contributing to a more equal society.
In what way is it economic wishful thinking?
Increase the personal allowance, increase the basic rate band. The added income received will get spent, that will mean increased VAT revenues, lead to more jobs, which leads to more corporation tax,more income tax and more VAT revenues.
Unless you are economically illiterate, that is economic fact.
It's not about reducing the total tax take, or ignoring the benefits taxation can bring.