This post and some of the comments seem to me to have got the wrong end of the stick. Sometimes offense is used as a rhetorical trick, in which case notions of 'high status response' and 'manipulation' are appropriate. However it normally occurs when one person - from callousness or ignorance - says or does something that does not accord another person's the respect and dignity they are entitled to.

When someone says something offensive to you - they're racist, homophobic, sexist - it seems like you should be offended by that. To a large extent your reaction will be non-rational, emotional, habitual. But to the extent that you can shape your reactions (or character traits), this seems like one you'd want to keep. In addition to the positive social effects, it seems important at a personal level. The offender is disparaging your identity, your dignity, your self-worth - they're not according you the respect you deserve as a person. How dare they!

By getting offended - and even better telling them off - you're often reaffirming your self-respect. It's an important, powerful moment when a wife stands up to her husband, when a gay kid stands up to bullies, when a black person calls out a bigot. When there's so much contemporary emphasis on challenging everyday misogyny, homophobia and racism whenever it occurs, it seems strange that you would be advocating the exact opposite.