No, I'm not just ranting about that expression, but it reveals a lot about how many people see history. *Back in the day* says to me that you're not all that interested in history, or chronology. And since the *back in the day* group is by far the largest out there who are interested in popular history, I tend to be cautious when I am talking, or listening to, these people. But, really, *back in the day?*
If you're wondering what Phoenix, Arizona was like before the area was *ruined* by *the white man*, or Mexicans, or whoever you would like to *blame*, just take a look at the Sonoran Desert. It hasn't been *ruined* at all. Yes, Phoenix is big, but the Sonoran Desert is bigger. And it's been a desert for 10,000 years. And, unless *back in the day* refers to the last ice age, this desert area, which stretches down in Mexico, hasn't really changed all that much.
Sure, there have been rainier times, and dryer times. There have been cooler times, hotter times and much hotter times. But it's a desert. If your vision of the Sonoran Desert *back in the day* is that rivers ran all the time (instead of being riparian), I guess I can't blame you. It sounds kind of nice. But the reality is that this has been a harsh place for thousands of years, and the people who have managed to live here have had to work very hard.
If I may, I would like to suggest that you just add an *s* to *back in the day*, such as back in the days of the Hohokams, or back in the days of the Phoenix Settlement, or back in the days of the invention of air conditioning, or back in the days when the 1-10 freeway was being built. I'm not asking you to memorize dates, I sure can't. I'm just asking you to take a closer look, that's all.