When I invest in a book or movie, I like to have some sort of grasp of what the whole point was. I don't exactly mean I need a huge background explanation to know why someone did what they did (I know that's kinda what I wrote - misspoke), but something to add some closure.
Now, I realize in life people don't always know why they did what they did. To me, if a movie or book does its job, then that will better conveyed, and it will feel more part of the story...that the act was random. In ATM, it did not feel the randomness was natural...to me anyway.
Also, it wasn't totally random (he picked the ATM), as shown by the pictures the bad guy had at the end, which brings me to my main question...again, what the hell was the ending about? The very end and throughout the credits? That is my main question.