Yes, I would say so, on the average.

I think that people leaving a country are more likely to dislike that country than those staying.

It's possible a lot of people would like to leave but can't. Also, some people would like to return, missing the cultural aspects of the country they left behind or their families, but can't because they're unable to sustain themselves there, they need to continue helping their families economically and depend on the higher wages of where they're residing, or they're afraid because it's dangerous.

Any number of things may be true. But one cannot sensibly infer those things from this sample of people that is very far from being a random sample, but is actually a heavily selected sample. If you're really interested in the state of things "back home", don't seek out a group of people who are very likely to be slanted toward having a particular view (whether that view be positive or negative), and when they express that view conclude that all must have that view. All may have that view, but to conclude that it is actually the case, based on such terrible evidence, is totally absurd!

I'll grant you that it's not a random sample and that there will be some skewness in opinions. But ignoring the wider context of the journey that these people must have made, and considering the nature of totalitarian governments, it seems to me that you're taking an obtuse position.

It seems that you have come to agree with me, but haven't realised it yet! You're saying that we must look at more than just the skewed sample, and that's exactly my point.

I don't think that's correct. The point is you can't just dismiss based on selection bias.

You could say that the survivors of the Titanic didn't want to drown, sure, but you're selecting for the people who survived. The people who all drowned might have wanted to!

I.e. there's a balance. People basically always migrating in one direction must tell you something other than "those exact people just wanted to".

Can you please point out for me specifically where you and I disagree?

I'm a different person. But the previous person said "yes it is a skewed sample, but the sample is still useful information" and you said "exactly - we should look outside the sample for information".