Dev Activity Custom Rom's topic

Guys now for one thing i want to make it clear i am not complaining just wandering. How come therebis not alot of dev activity for custom roms. Now i dont like cm12 never have never will on any versions. Is this the normal thing for sony cause i looked at z3 forum even the z1 compact and there isbhardly any customs roms.

As I said im not complaining just wandering