I don't like to feel duped.  I'd rather find a fun way to "grind" whatever currency to get X item than get it with a card.

At first it was because I was going to school and working and didn't have the money.  At this point that's not a problem but I just can't bring myself to shell out 10-20-40-60 just so I can have a shiny doodad in a game.

GTA: Online was the closest I ever came to forking over but I resisted.