that's what I thought also except last night I was the TEC...didn't build any cap carriers and no pervasive economy. Teams were locked. I was doing a comp-stomp with my brother and the other income (credits, metal and crystal) started showing up within 15-20 minutes (I'll check the graph more closely next time) and by the end of the game I had double or triple what any of the AI players had from "other" and he had the lowest income for credits and was zero for the resources.
Would destruction of trade and refinery ships come under this category?