Why are the crystals in pillow basalt smaller than those in many other examples of basalt?

A factor that determines crystal size in igneous rocks is the speed in which the lava/ magma crystallised or froze. As pillow basalts form at mid ocean ridges where magma is erupted into direct contact with the cold sea water the crystals form very fast and are therefore small. Other basalts erupted on land still have relatively small crystals and crystallised relatively fast but overall slower then pillow basalts.