You made me realize there is a problem with this guy's wording when he says "try to ignore the content of the complaint". That's an overstatement. I would put it this way: try to address not only the explicit content of the complaint, but also the emotion behind it.
Why is that good advice? Because people often don't say, and perhaps sometimes don't even know, what their concern really is. They simply feel it. And until they feel that a problem is resolved, it isn't resolved. So it simply isn't possible to resolve things without addressing the emotions. Sometimes people try that, of course. And that's when you find yourself in the same argument all over again, saying: "But we already resolved this!"
I agree: solve the problem- if there is a problem. But don't work on the problem of why people are complaining pointlessly.
I think what the author meant was: don't get shaken or upset by peoples' seemingly pointless and illogical complaints. You can, most likely, defuse the situation with a bit of empathy and acknowledgment.
It's excellent advice, of a kind rarely heard in the hacker world.