LOL, Saxon...I know how you feel.
I have come to the conclusion that a neutral growth scale is useful for nations with powerful military units. Because it takes a massive army to invade them...and that massive army will start to starve, reducing its morale and possibly giving it diseases.
To keep my own troops from starving, I use nature forges like endless bags of wine. Nature is very easy to get into, even for nations that don't start with it due to the massive number of druid and jade sorceress sites.
The percentage your population grows is somewhat small. But I agree that it would come in handy in a long game.
I'm quite new myself...these are just some thoughts. My next project: Make iron faith ulm work. I think I may have figured it out, but I'm not sure.