An old Army motto goes "one man in logistics counts as ten in the field", meaning that inadequate resource allocation spells doom for an army, no matter how big. That also means that the logistics are the flesh and blood of an opponent's capacity to wage war. Eliminating Mass Fabricators, Extractors, or Power Plants will hurt an enemy's ability to build or repair units. In some cases, experimental units need constant supplies of energy and mass to function. Additionally, T3 Power Plants might explode to cause a chain reaction — an unintended, but welcome, consequence.