Walter White's actions throughout the series cannot really be justified. He and he alone makes the decision to break bad. However one can, by looking at the characters of Gretchen and Elliot Schwartz, understand the various forces that set him on the path to that decision. These are two annoying people, made worse by the fact that they are completely clueless regarding their own behaviour. It's revealed through flashbacks that Walter blames the pair for cheating him out of his full share of the company Grey Matter, which he started with Elliot years before the events of Breaking Bad. Now, the show never definitively comments on this one way or another. However, what's clear is that something bad happened, which Elliot and Gretchen appear completely unwilling to acknowledge. And this is the fact that puts them on this list, as there is nothing more annoying than rich people who feel like they have no accountability.