We've also had 20-30 years of politicians sending the "message" that paying less tax (or no tax) is something to be celebrated.
I.e. the ever increasing limits on tax free ISA.
The relatively recent tax free amounts for dividends, interest, etc. The lower tax free threshold for "gig" economy such as renting a garage or a bit of freelance work.
Then we had Gordon Brown introducing a 10% basic rate tax band and a 0% small company tax band.
Tax efficient investments such as venture capital trusts and enterprise incentive schemes giving not income income tax relief but capital gains tax relief too.
Then the political footballs of increasing/decreasing basic rate income tax, corporation tax rates, higher rates of tax, etc.
Politicians (of ALL colours) have happily encouraged tax-saving behaviour for 20-30 years and sending a message that they should be celebrated for reducing peoples' tax. It's completely the WRONG message to send when we need people working and paying tax on both their wages and savings/investments.
(Of course, it's all smoke and mirrors because we're more taxed now than we've ever been, due to the never ending increases in indirect taxes (VAT, fuel duty, gaming, tobacco and alcohol duties, VAT on heating, insurance premium tax, etc etc).