I agree that there are people who fiddle their taxes, but that's not a reason not to make taxation the way to finance care - we just have to crack down on it, reduce the loopholes and prosecute those who try to evade tax (and their advisors).
The burden of tax always falls on those on PAYE, I think, but it seems to me doubly unfair that these people are then hit again when they need care (and I apply this thinking to any form of means test). We've seen on this thread that people in care are employing advisors to maximise their money and not pay as much as others. I'm not for a minute saying that this was not legal, or that I wouldn't do the same, but maybe it shouldn't be? I don't know, as I don't know what the advice was, and if I did I wouldn't know how fair it was.
It would be fair if everyone paid tax up front, though. And whilst you aren't keen to pay for the tax-evading Mr Y, isn't he also the sort to spend all his money so that there is nothing left when he goes into care, whereas Mr X has paid his taxes and saved into a rainy day fund, only to have it raided when it's his turn to go into the home?
It was mentioned upthread, and got a bit lost in the posts, but I would also crack down on 'cash in hand' jobs (prosecute both the worker and the customer) and any sort of fiddling. People are quick to condemn anyone who does a bit of work when they are claiming benefit, but are often happy to save a few quid by paying the cleaner or decorator in cash.
A fair tax system has to be enforced rigorously, but IMO when we have paid up we should be able to make choices about what to spend, save or give away without the government deciding that we can only have up to a certain amount before they will claw it back pond for pound. It just isn't fair to take away some people's savings and at the same time pay the bills of others who have spent.
And I know that not everyone can save. I know that. But those who can't will get care paid for anyway, and that wouldn't change if it were paid for out of taxes rather than out of money clawed back from those who have. The poor would not be any worse off under 'my' system*, the rich aren't affected anyway (they never are) and the ones in the middle - the Mr X's - will get to keep what they have worked for all their lives.
*and none of the above suggests that we shouldn't equalise society so that more people can afford to save. We could do both if we had the will.