I'm not at all against having flags to identify a poster's country. I've identified what country and state I live in numerous times over the years.
My thought, though, is that many times a flag symbol is really almost meaningless.
For instance: one poster is from England, another from Scotland, yet another from Wales, and one from Northern Ireland. Does the UK flag really represent the diversity in these posters?
Or: I'm from New Jersey and another poster is from Hawaii, and we both get US flags?
We practically live on opposite sides of the planet!