It's from an interview in the Flash Companion book.
Now this isn't Wolfman saying he agreed with that perspective about The Trial of The Flash. Just how he believes it was received by editorial and fans."I understood though that Barry was a fairly boring character in terms of his personality. By the 1980's, comic books had progressed to have stronger characterization, but The Flash was presenting that whole long, convoluted prison story ["The Trial of The Flash"], and I think that may have really hurt the character in everyone's mind. DC believed at that point Barry Allen couldn't be redeemed."