Someone remind me, was there ever a reason given why Scoot Mcnairy's character didn't question why he wasn't getting disability and pension checks from Wayne? Or why it was never brought to anyone's attention that the checks were being returned with inflammatory statements on them?
1. Because Keefe was returning the checks, not Lex (common misconception); 2. Because Bruce is blind... it's a reoccurring theme in the film.
First, to address the misconception:
It makes little sense for Lex to have intercepted checks and sent them with inflammatory messages to Bruce all along... there's no way Lex could have predicted it would cause Keefe to act as he eventually would, no way to ensure Keefe's graffiti protest and statements would be consistent with the checks, no way that 40 years prison for terroristic threats was part of the plan, and no reason to draw attention to his patsy well before his execution of his plan. None of this makes sense and results from a faulty assumption based off a single line: "Little red notes, big bang, 'you let your family die'!" The common interpretation is, "I am responsible for all these things."
However, Lex is speaking in clipped phrases, he's listing the things that pushed Batman over the edge. Note the "You let your family die!"
is one of the "little red notes" which makes it an odd thing to list
separately... "little red notes" is
inclusive of "You let your family die!" so there's no reason to say it... additionally, "big bang!" is in between, so it isn't a parenthetical... it's a separate, different list item. That suggests a distinction or difference. Some reason that "You let your family die!" needed to be specifically cited of all the little red notes.
My suggestion is that Lex is claiming credit for that last note as his, but only after copying Keefe's pre-existing protest in returning red-note checks and red-letter graffiti. Again, nothing
explicit in the film has Lex claiming responsibility for the notes or intercepting checks. That's purely
interpretation of a line... one that you're free to interpret in a way that's more rational and consistent with the facts and story.
Second, why would Keefe return checks?
The obvious protest is that turning away money is against his self interest, but Keefe has already proven he'll do things against his self-interest for the sake of making a statement. The "False God" protest is perfectly in line with that. He does it in broad daylight, in front of cops, at risk of a 40-year sentence, and yelling when the cameras are on him. It is completely plausible that Keefe would do something self-destructive if he thought it would send a message.
But what message is he trying to send? It's literally on the checks and in his protest and in his before-the-press remarks! There's too much material and nuance to parse completely, but to sum it up, he has a grudge against Superman and resents Bruce for trying to buy him off rather than take on Superman. At Heroes Park, Keefe doesn't protest the absence of checks because HE was the one returning them. His objection is to Superman and his statement is trying to drag Bruce into that fight.
Third, why wouldn't the Victims Fund respond or alert Bruce?
Precisely for the reasons Keefe is upset about. The Victims Fund is only equipped to pay people. Keefe wasn't helped with counseling, a job, support groups, or a platform to speak from. He loses his manhood, his job, his family, is angry, and the Victims Fund tries to solve all of the above with money. If Keefe rejects the money, they're not in a position to provide anything else, they're a fund, that's it, not a foundation or a support group or political activists or anti-Superman league or whatever. They have one tool: Money. If he doesn't want the money, he doesn't have to cash it.
It's as blind, callous, and insensitive as Keefe accuses Bruce of being (which is why Bruce is on Keefe's Superman Shitlist wall
too). Keefe is just as pissed at people perceiving Bruce as a hero who saved
him as he is of everyone thinking Superman's a hero.
Note Bruce
is blind. It repeats throughout the film again and again. Bruce doesn't see Clark's humanity, he doesn't see Lex's legitimate invitation or daylight legal maneuvers, sees Diana only as hot thief, etc. Note Keefe only comes to Bruce's actual attention for the exact same f'ed-up assumption a lot of the audience makes... Keefe says, "I have nothing!" and Bruce's first instinct is, "Wait, he doesn't have money? He isn't getting the checks we sent?" That makes a certain sense, but at the same time, even if Keefe had six figures in the bank, he could easily still say he's lost half his body, his job, his family, his peace, etc... and call that "nothing." Bruce should be extremely aware that you can have money and still feel complete loss, but instead he's so caught up in his own drama he behaves as if the cure is monthly checks. Is it any wonder Keefe would be outraged?