I genuinely prefer the parliamentary monarchy system to that of a presidential one though, no one individual has the right to veto parliament or pardon people without consensus. Turkey and to some extent the US over the last 3 presidents has seen increased power of the executive, I can honestly only see it ending badly.
The only possible exception to this rule might be when there is a royal wedding. But if you add up all the revenue generated by tourism during one of these events then subtract the amount of money wasted by supporting the royal family's lavish lifestyle during that and intervening years (not to mention the cost of the wedding itself) and I'm pretty sure you're still in the red.
TMW: I don't believe you. There are laws, which are enforced, that require special reverence for the royal family that is not afforded other British citizens. And more beyond that by tradition if not law. For example the queen's consent is required for all laws and prime ministers to serve, she is immune to prosecution, and she is protected from certain kinds of criticism or mockery. I know keeping portraits of the queen on your desk like I've seen many of my coworkers do is not mandated, but it is still repugnant.
If the net impact of the royal family on the country is negative, and you admit that it may be, then my never having done anything for the UK is, in effect, doing more. 0 is less than a negative number.
If by "for" you mean "in favour of" then you have a point.
Clearly it is not good that people are in prison for criticising Bhumibol. However there is no one in prison for criticising Elizabeth II.
I reckon, having lived there for a longish while, the Queen goes to USA because they want her there, to some extent a bargaining chip for UK diplomacy. USAmericans are remarkably gushy royalists compared to the British or Canadians or Australians etc. Getting a visit from our monarch is huge prestige for a President. I do not know of another world leader to have the same effect on them.
Trump went weak at the knees meeting HRH, even the teeniest tiniest bit deferential in the face of this astonishing woman's authority of experience and that is very very rare to see in him, though he didn't lose all of his total kackhanded attempted decorum.