there are definitely some good arguments for universal healthcare, but software devs should not delude themselves that they will do any better than break even in most cases.
edit: probably not true, I didn't investigate the UK tax system enough.
edit: On an individual level, a lot will depend on your income, and how expensive your US health insurance is. Here is an informative post:
https://www.quora.com/If-you-make-100-000-in-UK-what-percent...
That works out to about $560/month for someone with a salary of $100,000. If you take into account employer contributions, that's still less than a lot of Americans are paying. If you're on a lower income, you're likely to be paying significantly less in the UK for much better coverage.
And I almost forgot - copays! The amount you're paying in taxes in the UK really is paying for virtually the full cost of your treatment when you're sick.
It would quite possibly be a net saving. The UK, for example, spends less public money on healthcare than the US. There's no necessary reason why you should end up paying more in taxes for universal coverage than you pay currently for insurance.