The entire show needs to be turned on its head.
No one thing can be a solution at this point.
Give the heels or faces a strong direction, and they would still have massive issues with their booking, presentation, stigma attached to wrestling, etc.
But to stick to the topic at hand....I'd say that their problem has more to do with basic characterization than it does the dichotomy between heels and faces. Regardless of alignment, we are barely given enough to know ANY of the characters.
They aren't given enough backstage and promo work. The WWE relies far too heavily on in-ring storytelling at this point. It's resulted in RAWS full mostly of 3-star plus matches that mean absolutely nothing.
THIS. They used to get them both right. Yeah, early 90's had a steep falloff into cartoon land, but they seemed to get when to pull the trigger better. We all know it's because they had competition and wrestlers had more mobility to move around to territories they got the best push.
Heyman's Smackdown years were perfect with this too, and I preferred it over Raw. They don't really storyboard their characters for at least a year anymore. You don't see ANY stories really developing or feuds made semi-permanent (outside alignment turns). With lack of creative energy comes more reliance on in-ring performance, over and over, and dudes are getting hurt more for lower draws.
All I know is one of the solutions is to pinpoint trust your prime performers and give them the mic, and allow them to succeed or fail. There's so many in development and indies, that you got to see what you really have. Be patient with those with real potential and endeavor the rest. You may even get some Christians out of it.
This isn't working (well, before this week...there was some progress).