#4 Batista loves the pro wrestling business

Shortly after WrestleMania 35, WWE released a great documentary on the road to Batista's final match in the company, and the documentary revealed that the wrestler-turned-actor is a very passionate individual.
Prior to his return to compete at WrestleMania, Batista's previous run in WWE was marred by creative botches and a heel turn forced by the fans when they rejected The Animal's Royal Rumble win, preferring Daniel Bryan win the big match.
Batista was clearly unhappy with the run and wanted to return to the business he loves and respects so much in order to put real closure on an incredible WWE career. As mentioned, the final feud for The Animal was probably not what fans had hoped for, given its hot start with Batista attacking Ric Flair.
Despite Batista's movie career thriving before and after his WWE departure, it's possible that Batista's genuine love of pro wrestling and WWE could coax him out of retirement at some point down the line for one final hoorah at WrestleMania. The idea seems like a long shot, due to Batista's adamant claims that his career in the ring is over, but the phrase "never say never" applies to pro wrestling more than virtually any other profession, so anything is possible.