Well there are plenty of reasons for using what the system was designed to use. Saying that any one coil can work in numerous installations is sort of like saying we should make all shoes size 12 cause they would fit me and just about everyone else, even if they might be a little loose.
Specifically the design of a coil ignition circuit depends upon the inductance and resistance of the coil to allow the control circuit to do a good job at all conditions for a long time. The current that flows through a coil changes from coil to coil and in many systems is either limited by the control unit or is anticipated by the control unit. If you use a coil that needs 8 amps to make full output secondary and your control unit limits at 6 amps then that hot coil doesn't even warm up. If the control unit is an early unit without limitation and the coil draws 50% more current, the control unit won't last long carrying the extra load.
Control units have specific circuitry that handles voltage spikes caused in open circuit conditions. This spike voltage is also dependent on coil construction. If you were an engineer you would express the RLC circuit with Laplace Tranforms a variation of a differential equation. Do you suppose the variables in that equation don't matter.
Bosch Master, ASE Master, L1
33 years MB technician