Yeah I don't agree with Ryback on much, but I see his point here. The thing is, exposure, booking, TV time, etc play a huge role in drawing power and that's not often under the performers control.
If the company wants someone pushed, and they constantly give them TV time, put them in big feuds, they're constantly on PPV, and the company produces a lot of merch for them and pushes it.
And then on the other hand, you have someone who barely can get on TV, is given lots of meaningless stuff to do, and has like maybe 1 or 2 not very well made pieces of merch shoved out there randomly.
Well of course the former is probably going to sell more, but that doesn't automatically make them better. It just means that the company has stacked the dead very much in their favor, so to then turn around and go "well we should pay them more because they sell more" seems iffy because it's not an even playing field.
I mean WWE tried to cram Roman Reigns down everyone's throats for years despite the backlash. But on the other hand, when Zack Ryder got himself organically over, he was PUNISHED for doing so without the company's permission by being buried and then mostly disappearing from TV.