I think the top-level comment ("Might his squadron be called in to quash civil disturbance? Sent to the next Iraq? Is it reserved for defending the UK from invasion?") is exactly the kind of thing you should ask yourself when joining something like the Army Reserves. Everyone has some things they will not do, and it's important to figure out what those might be before finding yourself pushed to those limits.

The thoughtless comments basically express the idea that no one should be in any military, whereas thoughtful questions acknowledge that not everyone has the same red lines.

FWIW I was asking because the 3rd paragraph describes the Yeomanry as being founded to prevent invasion and "formed to serve only within Great Britain" and so I was curious if it was a special-purpose unit still (and I asked about civil disturbance as clearly at some point that was a function, but perhaps later civil rights changes prevent the use of the army for policing like in the USA).

But it doesn't really matter what my intention with the comment was, clearly I touched a nerve and most folks are replying on the ethics of the issue. That probably means that it is actually an interesting topic of discussion.