I'll try to keep it relatively short. The metro area is experiencing strong job and population growth. Historically this has mostly occurred outside of the CoA, but millennials are really beginning to dominate the job market and they have different preferences than the generations before them. Those generations too, though, are valuing things differently, so the story isn't just "millennials want to live in urban areas", though this a big thing, but overall there is a stronger desirability across all generations to live in walkable, traditional neighborhood like environments. That isn't to imply everyone wants that, plenty of people still love the suburbs, but if you have a 5% shift in preferences you now have to account for 275,000 people (assuming Atlanta metro pop. of 5.5m) wanting to live in a walkable environment.

Now you have to consider Atlanta's options for walkable, urban environments are severely limited. These areas are experiencing concentrated growth. They're near job centers, they're walkable (or at least by Atlanta standards they're walkable), they have a certain cache, etc.

Historically the region isn't building more than it was. It is just previously construction was spread over a larger area (sprawl), but now it is more concentrated. If you look at historical building permits the region is not even close to where it was over a decade ago. Not even close. From 2001-2007 multifamily building permits didn't dip below 10,000. We haven't broke 10,000 as of 2014, although I'm sure 2015 we broke it.

Then you begin to add in factors you mentioned. There was the housing market collapse, despite your claims, loans are not nearly as easy to obtain as you make them out to be, and certainly not easier than pre-recession. There are a lot more hurdles. And while the housing market has stabilized that doesn't mean we're building at a level that we were before or to keep pace with demand. It just means pricing has gotten back to where they were a decade ago, if even (keep in mind certain areas have improved more than others).

Anyways, to summarize, the metro is experiencing great growth in terms of jobs and population. There are a lot of people who want to live in urban areas. The metro area basically went on pause for 3-4 years during the recession in terms of building, so there was a lot of pent up demand, a lot of this demand in concentrated areas. There is a lot of building happening in certain areas, but that building doesn't match the growth of the previous decade, so this isn't anything unprecedented, again, it's just more in your face to your average Redditor who probably lives in an urban area.

Also, this isn't an apartment, it is an office, I don't think it is a surprise to see an office tower considering job growth and the preference of people wanting to live near where they work.

Sorry for the ramble, hopefully that makes sense. It'd make more sense if we were talking over a beer as opposed to me trying to jot down my thoughts quickly on Reddit.