They’re loading up No Mercy because it is the last PPV of the third financial quarter of the year, so they want to be able to tell investors that they had a large number of network subscribers at that date.
(Of course, they’re still sending out offers to lapsed subscribers for three months free, so best to look at the number of actual paid subscribers…)
Smackdown’s woes really started with their underwhelming contributions to WrestleMania. I know WWE had their long-term story mapped out in advance for Orton and Wyatt but they really should have changed it. Once the two of them were an actual tag team and in a title feud with American Alpha the audience were genuinely into the whole deal, while Jordan and Gable, for the one and only time on the main roster, were also getting over. They should have just kept that title feud going until Mania and put Jordan/Gable over for the titles there, then pick up the Orton/Wyatt singles feud after that point.
This would have freed up the WWE title match to be Styles/Cena, which would have been a far more suitable championship match for WrestleMania and allowed them to make a bigger deal of Cena going for the (made-up) record number of title wins. Assuming that Cena still won #16 at the Rumble, AJ could have won it back in the Chamber without beating Cena, leading to a rematch at Mania. Styles could have retained to be firmly established as the top dog on Smackdown. In defeat, Cena then gets on the mic and cuts a promo about how some things are even more important than the gold, asking Nikki Bella down to the ring and then on with the proposal in a slightly less obvious manner.
Meanwhile, this would have freed up Shane McMahon for a match with the Miz. It wouldn’t have been pretty but it wouldn’t have needed to be. It would have been a logical pay-off for all those times Miz bullied Daniel Bryan knowing full well that Bryan couldn’t retaliate - but Bryan’s boss, Shane, could. Just a quick match with Shane beating up Miz for a bit and then he and Bryan can have a nice Yes-chant celebration for the fans afterwards.