But the demand for more programming isn't coming from the WWE audience. It's coming from their television partners, and ebbs and flows over time according to demand. The WWE delivers a larger and more lucrative audience to USA (to which to sell advertising to), and in turn USA requests as much programming as they believe the market will bear. It's not just USA; their C-tier shows are sold to the syndicated market, hence the reason for the existence of Main Event and Superstars. There's no real reason to watch the shows, but they pull in enough of an audience that broadcasters purchase the programming.
Historical example; WWE and WCW's growth in the '90s. RAW was a one-hour show in the early to mid '90s, and maybe one out of every four shows was "worth it". There were subsidiary Saturday morning shows going under different names, but they were basically today's Smackdown; every once in a rare while a title switch to get people watching, but not really anything important happening. Then, the Monday Night Wars took off and were widely received. As demand for more programming increased, Nitro launched on Monday nights, RAW and Nitro moved to two hours, eventually Smackdown and Thunder were launched, and eventually Monday nights had stretched into a 3-hour marathon. Half of Nitro and half of RAW would suck, Thunder wasn't really worth watching, and Smackdown was OK. WCW collapsed under the weight of their own financial mismanagement, and with the end of the Monday Night Wars, demand collapsed with it and the amount of wrestling hours per week shrank alongside.
Market forces dictate that there will never be a time when all WWE programming will be worth watching. When all WWE programming is worth watching, the audience is demanding more programming and is willing to watch some of the shittier programming, like 75% of RAW, Smackdown, etc. If the demand is there, the WWE and their television partners are going to fill it.