It's basically saying "I often disagree with this person, so when I agree with them I refuse to admit that they have some virtue and deserve credit for it - they are still broken and bound to be correct sometimes out of pure chance." You don't see how that's kind of pathetic?

No, because that's not how I interpret it at all. I already explained how I interpret it: since he takes virtually every position possible, even contradictory ones, without any apparent thought or reasoning, any positions which are good are that way purely by coincidence, and therefore aren't worth anything.

The proverbial broken clock isn't useless because you disagree with broken clocks and refuse to acknowledge when they're correct. They're useless because they have no actual connection to the information they purport to convey, so even when that information is correct, it's still useless.

If I make a random number generator that prints out values between 15,000 and 25,000, I will sometimes correctly predict the closing value of the Dow Jones Industrial Average for the day. That fact is not worth a damn, though.