I agree in part, people are also products of their time period and shouldn’t be judged by our own time period.
But with regard validating the theory of eugenics, the influence was catastophic for millions of people, so not inconsequential or “off-handed” in the least.
I don’t think we can let some people totally off the hook for their ‘influences’, even if they did not know where their influence would lead.
History is a harsh judge.
Marx was born in 1818, over a century after Locke's death. If Locke was a materialist, it had nothing to do with Marx's influences, or those of those who immediately influcencd Marx, notably Feuerbach and Hegel.