Here's the kind of thing I mean by "human working memory capacity" being "set tragically low": A 100-word sentence introducing a new concept is often annoyingly hard to wrap one's head around, compared to a longer and more "gentle" explanation.
The concept of working memory seems like a useful reduction of part of what makes intelligence work:
Most of us here think human intelligence can one day be increased a lot, because there doesn't seem to be a fundamental limit to intelligence located anywhere near human-level, but that's a non-constructive reductio type of argument.
On the other hand, it seems like there's an obvious constructive argument to why working memory should be able to be increased: Take whatever set of structures encode the current short-term brain's working memory contents, and analyze how big they are, like how many copies of some lower-level storage unit they have, and imagine architecting the brain to have more such copies of those systems encoding more memory contents.
Getting back to my question...
We all wish we were smarter, but we suspect that there are no easily-tweakable parameters that would yield a big increase in intelligence, or natural selection would have already tweaked them.
But doesn't it feel like working memory is an easily-tweakable parameter, and natural selection just didn't tweak it because it was good enough relative to the rest of the brain and the needs of the species, but it could actually be tweaked pretty easily in a couple thousand generations if there were the selection pressure to do it?
The reason it might make sense to say our small working memories are particularly tragic is if there is, as I suspect, a smaller counterfactual distance to them being larger and much more useful for modern life.