My wife and I had a big Batman movie marathon recently. I didn’t think to start with the original Batman movie from 1989, I actually forgot I owned it to be honest. I don’t own any of the other Batman movies until we get to Batman Begins, which made me feel a bit old when I realized it was released 15yrs ago.
So we watched all the “Bale” Batman movies and moved through the “Batfleck” movies, ending with Justice League. It wasn’t until watching “The Dark Knight Rises” followed by “Batman v Superman” that I remembered a theory I had.
At the end of “The Dark Knight Rises” we see John Blake (first name Robin) discover the Batcave, and in “Batman v Superman” we see a case with the Robin suit that has obviously been spray painted by The Joker. We can assume Robin was not in any condition to stop it from happening, and we can further assume it was for painful, if not fatal, reasons.

My theory links to the two movies. I like to think that John Blake took up the mantle of Robin and tried to continue Batman’s crusade. The Joker and he had a confrontation that didn’t end well for Robin, and after that horrific episode, Bruce Wayne came out of retirement. It would also explain why Batman was much more violent and “un-Batman-ish” in the amount of fatalities that he likely caused in Batman v Superman. (Which is very much a stretch for my suspension of disbelief, but I can make it work.)
On a side note: personally I didn’t think that Ben Affleck was a bad Batman. The greatest flaws with “Batfleck” were in the writing. Batman is all about self control, and too many writers like to try to make him funny. Don’t make Batman funny, he is always the straight man!! If you want a laugh put him in funny situations! Like this:
Like I’ve said many times before though, I forgive movies easily and often, and though BvS had many things it did really wrong, it also had many things it did really right. A lot of Superman’s scenes were great. Well…… ok… looked great. Both of Batman’s suits were AMAZING!(I especially liked how they did his voice.) The fight in the warehouse was spectacular. Wonder Woman’s intro gives me chills every single time I watch it.
The high light for comic book nerd in me though is the ‘blink-and-you’ll-miss-it’ throw back to The Dark Knight Returns comic:

I mean: come on!!