I agree with your first part. I can't really add anything except it can indeed be appalling, the practice of tipping. Recognizing that, it's a shame that's what's expected, but it is, so I tip. (NOTE: I).

But as to the $10 v. $40 waiter, in my book, the tip is based upon the amount of the meal, not after that, as in "but, both waiters did the same amount of work." I'm not harsh, but this isn't my problem to address - I happen to know career waiters who take their jobs seriously, professionally, and are expected to manage in a pinch, fill in when others are sick (try getting your 9-5 people to assume the responsibilities of people out sick for a day), and in $40 restaurants, they are expected to have polish, knowledge of wines (if there's no sommelier), timing (in order not to rush diners), command of English, personal skills, etc. The wait jobs at $40 restaurants are harder to get, and so you are paying a larger tip to someone who is probably better at what they do. There are waiters at the steakhouses in New York who make a lot of money, work there forever, and retire comfortably. Ditto the places like Lutece, etc. If you have been there (I have been to some nice places), you know the service is typically SO superior (though there are indeed exceptions), and you can say WHY it is superior, so to make a long story short, they make more because they've earned it.