Why didn't original Palpatine survive Death Star II?
Back in 1983 it wasn't really a debate, the Emperor was dead, his best troops defeated by Ewoks, a tiny pin-prick A-Wing engulfed the bridge tower of the Executor Super-class Star Destroyer into flames, and the Death Star II exploded shortly thereafter. George had to end his trilogy so the corners had to be cut to do it and quick.
However, since then we've had the Expanded Universe (1977-2014), novels, comics, PC & console games, Special Edition, prequel movies and now Disneyverse (2014-), sequels, spinoffs, cartoons, you name it.
For some reason, Darth Vader (Anakin Skywalker) tossed Emperor Palpatine down the Emperor's tower (not a reactor shaft, the Emperor's tower is at the very top of Death Star II), thinking that it would end him when after seeing all the above canon and non-canon works of Star Wars, one would simply deduce that Vader would realize Palpatine could easily slow his descent onto one of the below catwalks, and make his way back to the Throne Room using force jump (or a service elevator), surprising and ending Luke and Vader at their most vulnerable.
Instead, Palpatine keeps firing lightning, screaming like an idiot, and falls to his apparent doom, not even attempting to slow his descent or grab onto one of the many catwalks below. When Palpatine reaches the strange electrical glow below, he turns into a bluish-purplish mist and the rest is history.
We could say it was all part of Palpatine's plan to die and then re-emerge decades later in a failed attempt to take over the galaxy, but why bother with that when he could have re-emerged minutes later and wiped out Luke and Vader very quickly?
I suspect the force lightning and his hatred of Luke probably had something to do with him losing control and falling to his doom, but it still seems odd.