Physics is an empirical science with a rather neutral language to communicate its content. Arguments (much more 'findings') can be translated to this language and be understood on their own.
The language of philosophy isn't so clear (or it is, but everyone has their own). Therefore an argument might not be fully understood on its own. The author/ philosopher might have tried to do so, but eventually it is easier to understand an arguments if you know what the state of the art was back then.
My point basically is, that this goes beyond 'motivation' - which is hard to illustrate if we look at physics for comparison.
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Unrelated: What's better: "My point basically is, [...]" or "My point is basically, [...]". If I knew how to ask this, I'd google it.