Saxonism is a name for the attempt to raise the proportion borne by the originally & etymologically English words in our speech to those that come from alien sources. The Saxonist forms new derivatives from English words to displace established words of similar meaning but Latin descent; revives obsolete or archaic English words for the same purpose; allows the genealogy of words to decide for him which is the better of two synonyms. . . . The truth is perhaps that conscious deliberate Saxonism is folly, that the choice or rejection of particular words should depend not on their descent but on considerations of expressiveness, intelligibility, brevity, euphony, or ease of handling, & yet that any writer who becomes aware that the Saxon or native English element in what he writes is small will do well to take the fact as a danger-signal. But the way to act on that signal is not to translate his Romance words into Saxon ones; it is to avoid abstract & roundabout & bookish phrasing whenever the nature of the thing to be said does not require it.
H. W. Fowler, A Dictionary of Modern English Usage, 1926.
There was a minor craze for [Saxon words] early in this century, giving us all manner of quaint pseudo-archaisms like skysill for horizon, but it has passed, and with it any notion of a special virtue inherent in 'native' roots. It remains broadly true that, as compared with derivatives of Latin, a decent proportion of Saxonisms in the vocabulary is a sign of a good writer, but the reader should never be allowed to suspect that this is the result of any conscious policy of choice on the writer's part. What 'a decent proportion' amounts to cannot be defined, and it seems easier and safer to approach the problem from the other end and work on the principle that a preponderance of classically derived words in what one writes, especially words denoting abstract qualities or things, especially polysyllables, especailly those ending in -tion or -sion, is a bad sign. That is Rule 1.
Rule 2 annoyingly goes back a little way and says, Never choose to write one word rather than another on the sole ground that it has an Old or Middle English pedigree and its competitor comes from a Latin, French, anyway non-English root. In particular, never choose an English-descended word like forebear when a foreign one like ancestor seems more familiar and natural.
Kingsley Amis, The King's English: A Guide to Modern Usage, 1998.
So, "avoid abstract & roundabout & bookish," but prefer "familiar and natural" terms. Yet what of questions of propriety and obscenity? These seem wholly orthogonal to matters of clarity and elegance of expression.