Because Photons(light) is/are way too slow.. disgustingly slow.. silly slow, universally..
Just getting around in one galazy photonically is way too sluggish to be practical.. Going from one galazy to another would be silly.. transversing the Universe (nobody knows how big it is).. is rididulous.. Light is the fastest thing we humans know of.. There must be something faster.. And Fester humans are slower than the speed of light.. which as I said, is way too slow.. for Universe maintenace..
God says he/it is spirit.. What is the speed of spirit?.. Actually God says we are spirits too.. Handcuffed to these bodies true, but not forever.. What is the speed of spirit.?.. Faster / Slower than the speed of light?.. I'm serious as a heart attack..
HEY!... you asked.... And I'm taking YOU seriously.. Good question..
Quantum particles? And they are such tiny little rascals that I wonder how many would fit on the head of a pin.