Well, I wouldn’t say you cease to exist, you just become one with the Force. The Jedi view this as a good and natural thing, and don’t cling to their individual selves. Qui-Gon’s trick seems somewhat perverse maybe, since it appears to be a resistance to the natural flow of things.
I seem to recall some piece of Star Wars writing, maybe one of the prequel novelizations, that suggested the Force itself was speaking to someone using the persona or voice of a particular Jedi. And if Jedi become one with the Force after death, potato potato maybe.