I do not think developers are ignoring downtown. Projects have been built recently downtown and many more were proposed till the economy tanked. Once the economy gets on solid ground there will be a lot of new activity downtown- An office building, condo's again and maybe some retail. Look at how much downtown nashville has changed recently. Just a few years ago there was basically no residential downtown.
I know reducing the carbon footprint of nashville is important and infill in nashville's core is important. But the reality is that there are only a couple thousand people living in downtown and one and a half million people live outside downtown in the suburbs and almost all of them do not shop and most do not work downtown. When the people demand to shop, work or live downtown then developers will build a lot more downtown. Developers have to respond to the market and it's demands. If you build it and the people are not ready for it goes bankrupt and that would be bad for our downtown. It is a slow process. The reason developers build suburban office buildings is because that is what the market and people want. And if you do not build suburban office buildings in nashville then the market and people go to the surrounding counties where they are building suburban office buildings.