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