Like I said, it's a personal choice that probably irks people
In the ROTS novel, Mace Windu and his use of Vaapad was a clear match for Palpatine. Yoda saw into the future that he could not win against the Sith. The Jedi of old were not prepared, so he left so he would eventually restore the order (through Luke). It is said many times that the Dark Side withers away the user's body.
isnt this how its suppossed to be, unless you disagree with your Master and end up killing him for whatever reason? we learn from our Masters point of veiw and use it to kill him, lol. the Sith are ruthless.
That is what it is to be Sith. The apprentice learns everytihng he needs, then overthrow the master to become Lord
of the Sith. But this is for another discussion as this is a thread about Plagueis.