I posted this before and here i will revive it during the knowledge crysis.
As we learned, we should not capture one planet out in the open just for the intention of knowledge raiding all planets next to it, but anyways,
Even with the expansion , low priority planets have no reason to cap besides resources, high priority at most has a ion cannon or omd or ars or af or special ship constructor.
My point is , when capturing planets with nothing on it, we should get something back besides resources, though you would say don't capture planets with nothing on it unless it's a strategical place or you need resources. interesting tactics to capture a planet you usually wouldn't but will cause you need something that it will give you such as ship cap, accumalative knowledge , tech tree bonuses or anything