Why should Nightwing be a champion in Infinite Crisis?
Well here's three good reasons...
1) Nightwing not only is growing in popularity but, is quite an iconic character in DC. From Robin, The Boy Wonder, to Nightwing, to Batman, and Nightwing again. Many of his stories have affected the DCU and it's characters. For example, his apparent "death" in comics recently.
2) DC has given so much airtime and merchandise to characters from Justice League. For instance, Batman, Superman, and Wonder Woman. Sure I can agree they're iconic characters, they're huge in fact! However, Nightwing hasn't fairly recieved the airtime, thought, and merchandise he deserves. Only recently has his character been given a little more coverage. After the cameo in Arkham City challenge maps, some best selling stories, being a playable character in Injustice, his appearance in Son of Batman, and his recent news coverage, this could be just the thing he needs to get up there with Batman, Superman, Wonder Woman, etc. and get the coverage he deserves.
3) Not only would Nightwing make a good addition to that game, because let's face he'd be a pretty sweet character to play with. He could also become yet another merchandise product like other champions and skins, which some people like me wouldn't be happy with but, would still be happy he's in the game. It'd be a smart and effective way to gain customers and players alike.
If anyone else agrees PLEASE feel free to express it and protest along with me. If you have other good reasons to add (again) PLEASE feel free to share it'd definitely help in the cause.