On the other hand
> In any case, the deeper questions of why the profession was thought to need a noun at all, and of Whewell's internal motivations, seem to me still rather unanswered.
I mean Whewell answers this in detail. There's no ambiguity about why the profession was thought to need a noun at all. It's clear they were looking for a single noun, not a string of words. And it's clear that the purpose was an overarching word to promote the unification of the natural sciences. And it's moreover clear it has nothing to do with trying to be inclusive of females at all (I mean Whewell even explicitly uses the word "gentlemen" to refer to these "proto-scientists").
I will re-quote the relevant portion of Whewell's 1834 review (and the only mention of the word "scientist" in the entire review) from elsewhere in this thread.
> And thus science, even mere physical science, loses all traces of unity. A curious illustration of this result may be observed in the want of any name by which we can designate the students of the knowledge of the material world collectively. We are informed that this difficulty was felt very oppressively by the members of the British Association for the Advancement of Science, at their meetings at York, Oxford, and Cambridge, in the last three summers. There was no general term by which these gentlemen could describe themselves with reference to their pursuits. Philosophers was felt to be too wide and too lofty a term, and was very properly forbidden to them by Mr. Coleridge, both in his capacity of philologer and metaphysician; savans was rather assuming, besides being French instead of English;
> some ingenious gentleman [this is Whewell referring to himself] proposed that, by analogy with artist, they might form scientist, and added that there could be no scruple in making free with this termination when we have such words as sciolist, economist, and atheist -- but this was not generally palatable;
> others attempted to translate the term by which the members of similar associations in Germany have described themselves, but it was not found easy to discover an English equivalent for natur-forscher.
It's hard to imagine a more direct exposition in 19th century English of Whewell's internal motivations.