If they have a sponsor and meet the reguirements, then of course they can live in that country. If they think they don't have to do that as they have a Human Right to live in that country, then that is not what Article 8 is about.
They can have their family life anywhere. Then can even have their "family life" in a third country, that neither of them is a citizen of.
Article 8 doesn't give them the right to choose the country they want to have their family life in, and never has.
Some post that they have a Human Right to visit the UK, after they have been refused entry. It gets pointed out to them that that is not what Article 8 is about. Others post and say they have a Human Right to remain in the UK when their visa ends as they prefer the UK to their own country, and they get told the same thing, Article 8 does not allow you to choose the country you want to live in.
I'm curious, because I've never seen you post much about yourself.
Have you actually experienced living in another country and having to apply for a visa? I know you are a UK citizen, I'm pretty sure you were born here...
I'm only writing in regards to a UK citizen marrying a citizen from another country and wanting to have their family life in the UK. Most people can only afford the option of UK or other partner's home country.
The whole 'moving to a third country' thing isn't going to be a viable option for most people as soon as the UK is out of the EU because then you have TWO visas to apply for instead of just one and all the associated costs. Not to mention the moving costs with moving two people to a third country. It makes my head spin...
Everyone else coming in on Tier 2 or Tier 4 visas, that have a strict time frame and don't lead to citizenship, is a whole OTHER story. Yes, it sucks to not be able to live where you want to live, but the truth is, tough. Times have changed, there is less flexibility in regards to international moves. Without legally binding ties to a country, just wanting to live there because you like it, doesn't give you the right to do so.
And why do people think they can just move to another country because they want to? Hollywood. No movie shows the actual process involved in an international move because that would be boring.