The more PPVs there are, regardless of how much money is made, dilutes the product. I don't think anyone can argue that. The shorter amout of time there are between shows, the less build you can do for each one, until they all seem like episodes of RAW or SmackDown that you have to pay $40 to see. It's pretty much an accounting trick, keep raising the price of the shows while the amount of buys drop so it appears as if the level stayed the same. It's becoming like the TV ratings where only the hardcores are left. WWE has gone from the undisputed #1 of PPV to a distant third. MMA is just smoking them silly to the point where you can barely find any bar or restuarant showing WWE PPV anymore. I thought it was a mistake when they raised the price of the lesser shows to be the same price as the Big 4 (well, WM has always been more), they probably lost a lot of people who were on the fence with that. Especially when you consider 3/4ths of WWE PPVs are not worth the price charged. Sure the hardcores are always going to buy, but you can't run forever on just the core audience.
In fact, HBO is doing with boxing PPVs what I suggested WWE should do. They're going to focus on fewer fights so they can be properly promoted and theoretically draw more buys. Time will tell if it pays off for them, but at the very least the people buying boxing PPVs are going to be seeing well promoted fights that will be worth the money paid for them.
What's going to be annoying is that WM is probably going to generate a ridiculous number due to the Trump stuff being covered by the media, which will just send the message to WWE that the way they do PPV business is just fine.