^^True, and also to CityLife's point, people in Jax have their own land and probably don't care as much about public land (though if you ask me it would seem most people don't care so much about their own private land either!). Though frankly, people in Atlanta also have land, maybe not typically as much (though the rich in Atl have far more land than the rich in Jax), but yards nonetheless, and that's a city with lots of truly great parks and high public and private spending on public land.
I think it partly comes down to attitudes. Folks in Jax are more "family oriented" and insular than folks in other cities, it would seem. While folks in many cities may have their own yards, as well, there is a greater propensity to want to share public space (and of course you want the space you use and share with others on a regular basis to be clean, safe and well maintained).
I think this is also evident in Jacksonville's nightlife. Only recently have bars begun to sprout up around the city, but Jax to me still seems like a "house party" kind of city.
Politics, too. Liberal people don't mind just throwing it up to the public pot of money, whereas more conservative people want to keep everything and "decide" what to spend their money on regarding public utilities/amenities/services (which as we can all see usually ends up being very little). I think there's a corellation between liberal cities and spending on things such as parks, social services, etc as well as concentration of bars and propensity to live densely/non-privately and play publicly (fewer families as a result), and then Jax and other consolidated/sunbelt cities would be the exact opposite (and thus attract more families).