it seems pretty damn plausible that some things are just too hard for some people to be realistically able to grasp them
Yep.
a lot of interest in IQ arises from sources we should be skeptical of
Sure, those are good reasons to suspect motivations, but not good reasons to stay away from IQ issues completely.
Ignoring IQ differences in social sciences (including economics) is likely to lead to… suboptimal conclusions and recommendations.
Crudely speaking, dumb people exist in large numbers and one should not pretend that this is not so.
Yep.
Sure, those are good reasons to suspect motivations, but not good reasons to stay away from IQ issues completely.
Ignoring IQ differences in social sciences (including economics) is likely to lead to… suboptimal conclusions and recommendations.
Crudely speaking, dumb people exist in large numbers and one should not pretend that this is not so.