How to deal with this situation?

For those not on the montreal community, there was a post this morning about tipping. Specifically, this person never tips in restaurants (or anywhere else), unless the service was (and I quote) "exceptional," which she admits herself doesn't happen very often.

Her rationale is (and again I quote, this time from the comments to the post), "what does [the waitresses'] choice of job have to do with me? i don't know them or care what they make. if they want to make more money, they should look for a different job," and, "what they are paid has nothing to do with me. therefore, i won't pay them more to do their job."

I'm flabbergasted. I want to comment, but I honestly have no idea what to say. How to you argue with someone who doesn't tip because he doesn't care about the waitresses? She *knows* they're taxed on tips, whether they get them or not (it's been explained several times in the comments); she *knows* waitresses are paid less than minimum (ditto); she *knows* tipping is a cultural expectation in Montreal (ditto again)... and she doesn't care!

I don't need a rush of people commenting on the thread. It's just that this is an attitude I've encountered before and have absolutely no idea how to respond once the points in the last paragraph are made. Anyone want to help me out?