To be fair, the OP said:

> The biggest culture shock I had coming to North America, how materialistic, exhibitionistic and keeping-up-with-the-joneses *the whole culture is*

And you replied

> My evidence is only anecdotal, but as someone who grew up in, and lived all over America, and lived abroad, *I couldn’t agree more with OP*

You then went on to share your anecdote, seemingly to back up your opening statement. Maybe it wasn't your intent to make broad claims, but when reading your comment in the context of the parent comments, it's easy to conclude just that.