Please get over it already guys, both of you. Walljumping exists in *many* different games as well as the cartoon and assumably manga of Dragonball Z. Who suggested what is really irrelavent at this point. Get back on topic.
And don't worry, you'll still take damage if you're thrown into a wall, whether or not you jump back off of it. Being able to bounce back off of it at the expense of some ki was made possible to maintain the fast pace of the ESF melee system and add a little style to the foray.
"Wall jumping" has nothing to do with being thrown in the first place though, at least not the "wall jumping" written into the ESF 1.2 outline. That kind of wall jumping will take place when you swoop into a wall and hold onto jump, allowing you to rebound back in the opposite direction without having to turn around.