I am scratching my head a bit at the people who say they "do not care" and then add a weakly-worded caveat saying "but I hope no harm comes to them". The whole point of their predicament is that they are facing a long period of imprisonment in a country where they speak not one word of the language, with the possible additions of torture and/or a death sentence. It's not like they got stuck up a mountain and are now starting a GoFundMe to pay for the rescue helicopter.
Yes, they shouldn't have gone. But they did. They now have to deal with that, and so does the UK government, and so in a very tiny way do all of us. We can choose (or not) to care about them as human beings, just as we can choose (or not) to think that children drowning in the Channel is a bad thing regardless of our position on immigration.
I should declare an interest here, because like a previous poster I know this couple socially a little bit. We are not super-close friends, and they live a long way away now, but we keep up on social media. And yes, when I found out they were going to Iran I thought "Erm, OK, good luck with that". But in real life they really are exactly like on the videos: Relentlessly upbeat, sometimes to excess. If you had asked me a few years ago "Which of your circle of friends would be most likely to go to Iran and get taken hostage", they would have been right at the top of the list. It's all very sad and I hope they will be able to come home soon.