Sure, but 25th largest city in the US is not "very very tiny". I grew up in a township of 4k people. That would be what I consider very very tiny. I was nearby a city of 30k people. I considered it a decently large city.
You're right, but the point is that Atlanta is overall larger than Portland in terms of being a major metropolitan area. The original post was talking about ATL's largeness and number of opportunities for youth.