Welcome back to "Doggerel," where I ramble on about words and phrases that are misused, abused, or just plain meaningless.
Whenever a skeptic points out a spectacular failure of some psychic, altie treatment, or whatever, there's always some woo who leaps to the defense by spouting this doggerel. This, however, completely misses the real skeptics' stance on woo: We don't demand that it operate at 100%: We only demand that it operate better than chance, placebo, or whatever baseline measurements are available.
There is a point behind popularizing spectacular failures: It means that psychics and quacks can fail in a manner that can't be easily ad hocked away. These failures often reveal the type of trickery involved, which can lead to a questioning believer to examine the lesser failures, and maybe even realize that their successes are meaningless and explainable without invoking magic.
Most woos who invoke this defense don't seem to realize that it's a bit of a backfire: If psychic powers always worked 100% of the time, there'd be less demand for a test. The fact that they don't work all the time is a good reason to perform a test: "Subtle" effects require rigorous experimental standards to measure, and it's not the skeptics who are afraid of that rigor.