"But Jim, how much knowledge does a holiday give you about a country's economic realities? "
You can, of course, only get a general impression - if you are interested enough, you fill in the gaps with reading, etc.
Why ask the question if the answer is immaterial?
Your American analogy is an artificial one - nobody is pontificating, we are giving opinions based on what we know (or believe we know).
The argument (often used on this forum), that you have no right to express an opinion on somewhere you don't live would make virtually all discussions on this forum null and void, as we all live somewhere and don't live somewhere else!
What they usually boil down to is "your opinion doesn't coincide with mine".
Jim Carroll