My CC spend per year is low and will only net me 30k points/miles max, so it would take a few years just to earn enough to use them if they were divided among 2 or 3 programs. I pretty much view miles earned on CCs to supplement what I earn from flying.
Have you considered signup bonuses? All of your yearly earning would be eclipsed by a single signup. (That's how most of us diversify, as we're left with enough miles in several programs to be useful, within a few months/a year.)