Rejection goes hand in hand with writing, and especially so if you're a screenwriter. See, us screenwriters put up with a lot of crap that other writers wouldn't. Could you imagine Stephen King or John Grisham turning a novel in to their publisher only to have it torn apart by producers, agents, managers, development execs, publicity flacks and various other sundry and nefarious know it alls? Stephen, not enough product placment! Hey John, where's the character arc, and oh, by the way, change the ending, it's too much of a downer.
Screenwriters must love being in hell because we spend so much time there.