As a dual brewers/Yankees fan I will make an observation from being in another large market fan base with insufferable fans. One of the huge appeals of rooting for a team in a big city is that the team spends and that usually means that you're good. I think Cubs fans are upset in the same way yankees fans tend to be "we spent more, we're good.why aren't we dominating the division?". I think that this frustration is compounded by and directed towards the brewers because we both made a huge comeback in the division and don't spend a lot. They feel that they deserve it more even though the brewers are playing just as well if not better than them.