Not to put words in their mouth, but I think part of the poster's point is that inability is is a more complex equation than simple biological capacity. A couple who judges it economically risky or otherwise irresponsible to start a family (which represents a wide swath of the population) could for example consider themselves unable.

No, this is a pretty typical conversation on the Internet these days: someone takes a relatively well-defined stance on an issue, and then someone else wildly misinterprets or misrepresents it, just to get in a dig at the original person for... Unclear reasons.

It's either terrible reading comprehension, an inability to understand nuance, or just plain trolling. None of these lead to productive conversations.