Being an immigrant gives you an edge of being more critical towards the country you reside in, for having been raised differently and thus instinctively noticing things that natives otherwise have been normalized to ignore.

In theory. In practice I see too many comments that use the phrase ("as an immigrant") as a way to turn their opinion (not always very smart) into some kind of fact. Look at the parent comment, it's not in the form "in my opinion as an immigrant". It's "as an immigrant I can tell you" as if that's something objective. Well, I'm not an American and I can't tell you that. Quite the opposite, in my opinion his comment is rubbish.