What about full lightning doesn't work would you explain please?
Lightning doesn't offer anything to either pve or pvp (full I mean- hybrid lightning is almost a must in pvp due to the stun bubble and force regen for healers- and even pretty popular for dps specs for the same reasons). You almost never see pures in pvp- but if you were it would be madness for the 2 second root.
Lightning is too immobile- in pvp that's a death sentence, not to mention LS, CL and TB all do mediocre damage. Madness on the other hand is extremely easy to purge and thus a healer near nullifies them in most cases- but at least you have more chance against non-healers.
In pve- madness has similar damage but with more mobility, and while mobility isn't as vital, it's still there- so lightning even takes a back seat there.
Ultimately- right now, lightning is used as a hybrid for CC and force regen, not for damage or pure specs in any case.
Now- before anyone says 'well I can top parses as lightning and own face in pvp!' yes, of course some people are able to do that- but I guarantee if you're good enough to get good results from a lightning build, you can get better from madness and even better from almost any other dps spec.
Sorcs are a difficult class to play well relative to almost every other class- and even if you do you aren't surpassing the good players of other classes.