all i know is whenever a sith and only sith use force lightning, they first decare how much more powerful they are than the jedi.
"as you can see my jedi powers are beyond yours...now back down" *zap*
"i have become more powerful than any jedi....even you" *zap*
"if you cannot be turned....you will be destroyed"*zap*"...your feeble skills are no match for the power of the dark side"
now, lets establish first that only sith use lighning. most find it obvious but some argue even that point. the evidence is there, the jedi never use it. they MAY learn of it, since obiwan unflinchingly blocked it with his lightsaber...so perhaps he had prior knowledge of such a technique. KNOWLEDGE mind you, not the know how or the will to use it.
so if that is accepted then the question is this.
do the jedi not use force lightning because:
-they dont know how to
-they are taught that it is a darkside power
well, yoda states that the darkside is not more powerful, just quicker, easier, and seductive. so perhaps using lightning is kind of a....boundless release of power...like letting the levy break you might say, a loss of control. we know that control is essential to a jedi, right?
so is it fathomable that a jedi has the ability to use force lightning, but the act of doing so is corrupting to them?
all i know is yoda absorbed that lightning like it was nothing. im sure he knew what was up, and how to defend himself. so if he knows how to block it, adn deflect it, is it not conceivable that he may know how to use it? i think so. i think he could if he desired, but the path of the light side forbids it...my take anyway.