I think the answer is because the writer put him in it.
I don't know why Plastic Man was ever even on the Justice League. The JLA is supposed to be the best of the best, and Plastic Man, simply isn't that. It's like having Howard the Duck on the Avengers.
Edit:nevermind looks like all the post were deleted. they need to lock this thread.
Last edited by a kiss to remember; 09-13-2017 at 10:15 PM.