Here is an example of my line of thinking:
Certain markets, like Orlando, Tampa, etc, are growing incredibly quickly, but there are close to no 1% deals.
For comparison, you could buy a 1% deal, or even 2% in a town that is losing population. Take most markets in the midwest for example. You can expect little to no appreciation on most of these houses.
Assuming 3.8% appreciation over 30 years (which is average), our Orlando/ Tampa house will have tripled in value. It's logical to assume that rents would follow, and now our Florida house is performing much better than our midwest house whose value and rents have risen much more slowly.
That being said, this is all in theory, but the logic seems solid. Given a long enough timeframe, would you rather invest in the place that people are going to or the place that people are leaving? It seems like the smarter option to buy properties that scale up into progressively better and better investments over time, than to buy one that starts out better, but fizzles out or stagnates.