I don't even think what MyOwnDrum said was the least bit insensitive. He was making a joke, for ****s sake.
Just the other day I was out with my co-workers having a drink, including the Irish guy I work with. (whose accent makes me weak in the knees, but I digress... ) He's telling this story about how he thinks we're too soft on kids here in the US. About how in Ireland, if kids do ****ty in some sport, they'd throw rocks at them and how in the US we give ****ty kids trophies. I said something about there being a 'happy medium' between the two. He chuckled and said, "Well, we wouldn't actually throw rocks..." and before he could finish I interjected, "You'd throw potatoes?" Everyone at the table busted out laughing and he did his damndest NOT to laugh and just TRY to pretend to be offended while he rattled off about Irish stereotypes and told me, "póg mo thóin".
People CHOOSE to get offended. People like that guy in the OP are only harming themselves by being pissed off all the time. He'd be so much better off mentally, and probably physically, if he laughed instead of angered.