If you want PvP crucible marks, play PvP there is no reason at all for you to be able to exchange materials for PvP marks. It shouldn't have been implemented in the first place. People constantly saying the Become Legend catch phrase is getting annoying, it is a bit autistic for people to get all sperglord over this game. People take it too seriously, and create their own fan fiction and speculation as to why things exist. Noone in my nearest vicinity in actual life would say, in Destiny, I don't fell like I can become legend. It is like if I was playing dark souls you constantly saying I was prepared to die, we all prepared to die people. become Legend is basically the same thing as saying, I am a furry I find animals hot.