Taking Exception

Does the phrase I used yesterday make any sense? To wit:

I fear that the weekly magazine is simply defunct in the age of the web. (The New Yorker and the Economist are the exceptions that prove the rule.)

A vigilant reader sends me here:

These days it is often used sweepingly to justify an inconsistency. Those who use it seem to be saying that the existence of a case that doesn’t follow a rule proves the rule applies in all other cases and so is generally correct, notwithstanding the exception. This is nonsense, because the logical implication of finding that something doesn’t follow a rule is that there must be something wrong with the rule. As the old maxim has it, you need find only one white crow to disprove the rule that all crows are black.

For it to make sense, I guess I have to unpack it some more. Somehow, David Remnick's New Yorker manages to be relevant each week without being exactly weekly. It's a monthly magazine published weekly, essentially, with some more newsy items thrown in for topicality. The Economist endures as a weekly not simply because it's so good and perfectly packaged - but because a hefty number of subscribers get their companies to pay for it entirely, or write it off as a business expense. Opinionated reporting is much more vulnerable to the web. Pure opinion almost fatally so, I'd say. I wonder how much longer the op-ed page will last as a viable form.