What did Sapir intend to say when he wrote that 'whither' repeats all of 'where'?

Question

I first learned of this quote on p. 105 Bottom. McWhorter, J. PhD Linguistics (Stanford). Our Magnificent Bastard Tongue (2009).

Primary Source: Language: An Introduction to the Study of Speech. (1921)

p. 181

Another instance of the sacrifice of highly useful forms to this impatience of nuancing is the group whence, whither, hence, hither, thence, thither. They could not persist in live usage because [1.] they impinged too solidly upon the circles of meaning represented by the words where, here and there. [2.] In saying whither we feel too keenly that we repeat all of where. That we add to where an important nuance of direction irritates rather than satisfies. We prefer

p. 182

to merge the static and the directive (Where do you live? like Where are you going?) or, if need be, to overdo a little the concept of direction (Where are you running to?).

1. How can these now rare Locative Adverbs 'impinge' anything, when their meanings can be distinguished from 'here, there, where'? E.g., 'there' ≠ 'to there', obviously.

2. How exactly does whither cause an Anglophone to feel 'we repeat all of where', when their meanings can be distinguished?

3. Was Sapir being politically correct? Isn't the true reason laziness or uncouthness by lay Anglophones, who simply forgot the meanings of the rare locative adverbs?

Answer 1

To (1): They can impinge. That doesn't mean they must impinge. And in historical linguistics, the diagnosis of a causation is not predictive that the same change will always apply. It's something that historical linguists of yore weren't always careful to caveat.

There are languages that differentiate directional and static locatives morphologically; it is a slight difference, and one that recurrently disappears from languages that have them. That does not mean that it must always disappear, or that it can't reemerge. So the distinction disappeared in English, and in Modern Greek, because it's the kind of relatively fine distinction that is susceptible to disappearing; just as palatals tend to be unstable diachronically. But that does not guarantee that they will disappear in all languages that have them.

Hence, (2) is a post hoc, Just-So explanation of the loss that I find unpersuasive.

But so is (3). People don't affricate palatals because they are uncouth; they don't merge morphological categories because they are dull, and they don't avoid hypotaxis because they are brain-damaged. Or at least, they are no more uncouth, dull, and brain-damaged than speakers of language that happen to retain some categories they don't (but drop others). It's droll to contemplate that Germanophones are superior to Anglophones because they retain a wo/wohin distinction; but it's also profitless; the couthness the Germans maintained in keeping wohin, they squandered in dropping the /θ/ that English kept. :-)

Language changes because one of the forces operating on language is increasing ease for speakers of producing language; language change is unpredictable, because there are multiple different kinds of ease being pursued by speakers in language (phonological simplicity vs morphological transparency being one classic unstable equilibrium; ease of production vs ease of intelligibility being the other), and it isn't the only force at work in any case (so is for example social capital).