>>35706276It's complicated. Some characters were burned from other stuff that had long since happened in the comics, and then it was just incompetent writing in general.
It didn't help Johns roping many characters who had since moved on from the Titans back into the the title (Beast Boy was particularly badly hit by this, and he ended up inadvertently being the David Wooderson guy from Dazed and Confused), and it certainly didn't help when Johns turned the Titans into a gory angst and deathfest, and the editors after he left the title forced the same tone on the writers that followed.
As for why Cyborg is the only one (besides Robin/Dick Grayson) that made it "big"... well, I think it's because he's the only black character Geoff Johns could think of. But then again, I'm a cynical bastard.