I think you mean "doesn't mean we can't", but you seem to be hyper-focusing on the summary statement I wrote, of the original author's post. That summary statement was in place to explain why your original post wasn't addressing the issue.
But that statement was summarizing a portion of the original author's post. If placed back in the context it came from, you can see the original author was not saying we cannot make meaningful changes. At all.
Instead, the author was said:
Aside from the fact that there's a subjective definition problem here (how do we decide what people "need"?), I think this an unrealistic view. By this definition, every government that has ever existed or ever will exist is a "bad" government because no government can ever tackle every single problem 100% of the time. Many problems are extremely difficult to solve (e.g. global warming), and others simply cannot be solved without creating other problems.
Thus, they are not defining this as a "we cannot improve things", but instead "if we improve things, some will see that as bad" conjoined with "in other cases, we improve things, but not as fast/completely as desired".
As far as I can see, there is not a single point that the original author said we cannot improve things. They don't even hint at that.