Injuries - The people who worked Raw and SD were going hurt by working 2-3 nights b2b on ppv weeks. Guys like Reigns are banged up, AJ and the Usos have had to skip house shows, Sasha got hurt once with her knee during the Revolution, etc
Maximize Creative - WWE has operated with two head writers but one collective writing team of 22 guys since the split ended, whereas they once had Gerwitz and his 9 guys and HAyes/HEyman and his 9 guys supervising a set number of talents. This means less shit needs to be mashed together because there are less agendas in the room
NXT Success - WWE has saw that a guy like Balor can draw in NXT and yet they have also seen the formula for NXT changed. Balor ushered in a wave that made NXT a brand that can sustain two tours and some smaller TNA indy darlings can keep their name that made them and work there to sell tickets nationally while the Performance Center crew sells out Florida and works their kinks out. Before NXT was small time and spinning its wheels with HEro, Zayn, Neville, but not anymore as they have a lot of ground gained to stand on their own.
MArketing - It is easier to market live events and TV if you have a set list of who is where and when. You can sell tickets as SD or Raw live as opposed to picking a headliner and randomly assigning them a undercard by ticket sales like they did when Orton and Cena led a tour vs Bryan and Punk. ORton and Cena always sold tickets so they filled themup with acts like Los Matadores, while they tried to bloster the other with more well known names. The same problem persisted with the injuries and the Ambrose and Reigns tours. Now you know who is touring where and the talent will also know their travel schedule and can plan their rest and life accordingly
Returns - WWE has never been in a better place. PEople hate Reigns but he's headlined two of the most profitable events ever. PEople love to jeer Cena but there is a reason he made almost 10million last years since he is a cash cow still and showed with his invitational he can make people look great. They have Cena, Rollins, Orton, Reigns, Brock, HHH, and both Stephanie and Shane ready and able to appear on either show at the drop of a hat. It is easily the most top heavy they have been since they lost the likes of Edge, Batista, Mysterio, Michaels as regulars
Vets - They have veterans to mix with both sides. They have the guys like Truth, Goldust, KAne, JEricho, Show, Henry, Dudleys, Miz, and people like KO, Zayn, Cesaro who worked indies forever. People ignore it but that makes travel, policing a locker room, and wlaking guys through matches and road life much easier like when they did the first split. The original spli worked because guys policed themselves and young characters like Lesnar, Shelton, Orton, Cena, Batista all had vets to learn from and grow around. Towards the end of the split they didn't have that as you had guys who had only worked FCW before trying to put it together on the big stage with no one to lead them as vets were going away or retiring
NBCU - Hammer who ran SUA is in charge of NBCU as a whole now. The WWE isn't trying to make things work with SyFy. They don't have the option of be taped and if you want to be live do it on Fridays. They don't have to be told you get no over run like with ECW. Now they are on USA for boith shows and they get promoted, brought to the Upfronts, and treated well. USA won't give a fuck if SD runs 10 mins late for a hot segment. The fact is WWE only killed the equality of things when they were shifted to Fridays as UPN started going dark. They gave SD on the CW talent and angles; hell they booked JAgged Edge to work the show once upon a time; it was just the move to MyTV that made them thin it back out again as they had less coverage and started losing markets. They just are in a much better spot with USA and Hulu supporting them ... E! and ESPN treating them good also helped but SD held its on on USA as it hasn't been lower than 3rd on cable on Thursdays since its transfer to USA and it has been number 1 five times vs the NBA and other shows. Raw is still their number one rated show and top ad revenue for USA, SD delivered so making it live means they have a shot at being bigger as they have proven to be the number 2 show for USA. Raw has also been the 4th most watched program on Hulu and SD the 7th on the calendar year and NBCU owns Hulu so they understand how many eyes actually watch the program both in replays and first run
MAnia - WWE saw they just set an all time attendance record, a merch sold record, went for 7 hours, got E! coverage, got ESPN coverage, did 900k to 1.2mil traditional buys, and had 1.5mil paid subs for MAnia without any huge names announced. It probably made them say damn when we bring in the names we can make Raw/SD separate and draw money from them