I dislike DLC's, but I think of it this way... I just think back to older games, and how DLC's could have improved them.
Like, take Dragon Ball Z: Budokai 3 for example. It's an amazing game, but it really lacked content-wise. The majority of characters feel unfinished, with clear possibilities in additional moves (eg. Krillan could have been given the scatter beam as a dragon rush finisher... hell, they even added Cell Jr into the game with only one ability). If back then they could have added DLC for extra moves then I would have been more than happy to buy it.
It all depends on the situation. If publishers obviously plan for DLC's just for the sake of making extra money... then yeah, that annoys me (CoD in an example of this... 3 dollars per map, a huge joke imo). However, if publishers plan for DLC's to compliment the base game, or add content that they were planning to have on-disk, but could not... then that's fine with me.