There is no problem with C&Rs if they are structured and worded properly and have teeth to keep the company shenanigans from unravelling them. When an arbitrator is involved, that makes it difficult as NO ARBITRATOR fully understands the fine points of how airline crews work, bid and progress, and how low management will stoop to undo an arbitrated award. Unless you live it, you can never quite "get it." For example, try explaining duty rigs to a non-crew member. I estimate fully half of the flight attendant cadre in this company could not calculate their own duty rigs if they had to, and they are living it day in and day out.
There is no doubt that any C&R language would need to be as ironclad as humanly possible, with specific penalty for the company to mess with them. It took many contracts for US Air(ways) pilots to get their scope language as tight as it is. But such things can be done with sufficient effort. Maybe the C&Rs that USAPA proposes are not as strong as they could/should be. Well, let's hear from the westies on how they want them structured. I think this is what the Ninth Circuit had in mind when they mentioned that a USAPA negotiated contract may not be harmful the west.