I gotta say I wish all lights had the same switch and placement
as the C and D mags. There's no need to move your thumb to the
back of the light, which I find to always be awkward.
Yup, switch on top of the tube is more ergonomic for me, and I'm certain it
must be for others.
While I agree we need more lights with a up-front switch like
M@G and millions of lights before them it is not always the best. I do love having the Proton-Pro though with it's forward switch.
Many highpowered lights were primarily used by military and lawe enforcement. These customers "need" the tactical switch, on many of their lights.
Many light light physical designs also work better with the tail switch, while this is a engineering issue, it's also a cosmetic issue for the customer so the tail switch has its astetic benefits for some as well.
You may have noticed the recent wave of twist-ring lights. These are putting the control up front, although many still include the tail switch as well so as not to lose the tactical customers, or for engineering reasons.
I love the new Eagletac M2XC4 with no tail-switch.