When I was in my twenties I lived in a rough part of St. Louis and worked in east St. Louis, which was known at the time as the Murder Capital of the World. Back then I carried a Para-Ordnance P13, with one in the chamber and an extra mag, which gave me 27 rounds of .45 auto, and never felt under-gunned. In fact, most of the time I felt my load out was a little much, except for when I went to work.
A few years later, I moved to the 'burbs and began working in a much safer part of STL. I started carrying my dad's old S&W .38 snub, no reloads.
Fast forward to four years ago when I moved to Anthem, AZ and have been working in a very secure environment for the last 8 years. Now my EDC is typically 8 rds, except for June, July, and August when the heat coerces me into carrying my LCP, holding 6+1; no extra mag. In the 'winter' (Nov, Dec, and Jan), I'll usually carry my 1911 with the 8-round mags, so 17 rds total.
If I could, I'd carry my 1911 year-round, and I even tried it for a couple years. However, although it can be done, it's just not comfortable when the temps climb over 110 degrees (I don't work in an air-conditioned office).
Or if I lived/worked in less secure environments, I'd probably consider carrying more rounds. But I just don't. Heck, I can't even remember the last time I was in a gun-free zone, which apparently are much more dangerous than gun-friendly zones. I don't try to avoid them, I just don't have a need to visit them it seems.