Because it's my money and the welfare on offer is not commensurate with what is paid in. Tax has a place but when it's up over 50% then it stops being fair.
As an example, my father ran a successful business for many years, fell ill and had to sell his business at an inopportune time. He'd always reinvested his profits into his company and if he'd sold it a few years earlier or few years later then he'd have had sufficient to comfortably retire on. As it is, he's 72 and receives just over £1,100 gross per month from his various state pensions yet he paid tax at the highest rate for decades and employed 20 odd people for all that time. My mother receives £64 per month as she was an unofficial secretary/housewife and thus didn't get a large number of qualifying NI years.
That's a crap return for what was actually pod into the system. I urged them to call the DSS or whatever it's called now and find out if they qualify for anything, and they don't apart from a modest council tax reduction. So I send a couple of grand back to the UK each month and have done since I emigrated to supplement their household income and to allow them some sense of freedom. If I was in the U.K., I wouldn't have the disposable income to do that.
If tax monies were well spent then there's a good argument for it, but on the whole, it isn't well spent. There's too much wastage. There's too much spent on defence for pointless wars, £13bn on foreign aid (including some countries with a fucking space programme), £20bn lost through public sector fraud, £1.2bn in CAP payments to foreign farmers. As I say, I understand a country has to provide protection, roads, schools, healthcare and the like to its citizens, but I don't see why grants of £92,000 on a skip covered in flashing lights by the arts council or why the FCA paid £50,000 for a logo change that would have taken anyone on here less than two minutes on Microsoft Publisher.