I like this idea over-all, it increases the cost of huge empires that grow rapidly. But I noticed that the 'negative' income never changes if you don't build up some infrastructure... this is Really annoying... it means I have to micro manage my planets even more.
Why doesn't the effect last for say 10 minutes of RT and then disappear... eventually the colony would 'pull itself up by its own boot straps'. To use a terrible presidential quote.