Our definition of "big", I think. I can't be sure because the article leaves it so loosely defined that one could cherry pick data to suit their mood.
Is no space project acceptably "big" simply because it doesn't include humans or habitats? We've been to Mars a few times lately, by robot. We're going to earth orbit far more efficiently these days. We're launching satellites at a furious clip. And for this, even though poor nations languish without proper electricity, they do have cell phones. Not to downplay the problems that remain, but that one seems "big" to me; at least worth mentioning.
To say nothing of computer vision. Processing power advancements have turned this long-suffering field into something of a white-hot ball of promise lately. The applications being developed will be at least as transformative as anything the automobile delivered.
Is this not "big" because the applications will first be delivered to wealthy nations, because some of them look like "toys", or because it lacks the old-school wonder of a big-ass rocket launch? I have no idea from the article; I can only infer the author disqualifies it by its complete omission.
And the author is similarly imprecise on who "we" even are. After identifying many of the problems they consider "big" as primarily international political problems, in many cases a result of international poverty, they then point fingers at the US political situation [1] when looking for answers.
Is it reasonable to expect that the national feeling that fed support for a US-centric space program is lacking because there isn't similar contemporary support for solving problems overseas? Not that the US couldn't do more on some of those problems [2]. But aside from the military removal of despots, the US has no real history of possessing the national will -- or even the capability -- to solve political and poverty problems overseas.
Even if we had that Cold War-era national spirit today, I'm not sure it logically follows that it would unite behind e.g. a massive political/research/development effort to light Africa.
[1] A mess no doubt. And one doing grievous harm to our national R&D.
[2] We could even "do more" by doing less in some cases: stopping support for programs that aren't helping, but are instead warping markets and political structures.