I happen to appreciate gary's sarcasm and see no inherent rudeness in it. No matter how skillfully sarcasm is delivered however, someone will always be offended by it or write it off as rudeness.
A little sarcasm now and then is good for the soul...a great release...like a good old fashioned rip-roaring fart. Some people see the humor in a big loud fart. Some think farting in public is simply rude. I say, if it makes you feel better, let 'er rip. I'll probably even laugh as long as it's not aimed in my general direction. Right now I'm just laughing at the ones complaining about the smell. Sometimes sarcasm, like a good fart, is best appreciated from a reasonable distance.