One of the things I loved about Waid's run is that when genuinely, world affecting, catastrophic shit happened in The Flash...he brought in the JL, and made them look good and do their job, despite Wally being the one who would save the day.
Nowadays the JL would just show up to tell Wally he's a shitty amateur who can't handle things on his own like Barry. The same people who praised him for the opposite for years. It's all so shitty.
And by the by, the "This is what they toss around in the editor's room" comment wasn't some guess. Brian Cunningham, Flash editor for awhile, specifically said DC has absolutely no interest in ever making a Wally series for the exact reasons we're talking about: It just seems like they'd be making two of the same book and diluting the main book by taking things away from Barry to give to Wally (despite the inverse being something they love to do). If your pitch can't get over that hurdle, then it'd never happen. On top of that, your pitch of just "A second Flash book that's just like a normal Flash book," if it DID happen, DC would rather it just be a second Barry book. Barry is more popular. If you were going to make a second book why not focus on the more popular, higher selling character? Not only that, you don't even have to split your villain/supporting cast catalog!