I'm sure I've confessed here before to being what others might call a "prescriptivist" where English usage is concerned. (I'm actually all for freedom of choice; it's just that I would prefer it to be an informed choice.) But I have a healthy respect for the power of practice to normalize things, including the way we speak. Like Canute, the eleventh century king of Denmark, England, Norway, Sweden, etc., I might as well try to hold back the tide as to buck the way things get said.
And King Canute, or Cnut, is a good way to broach what I'm on about today. Popular myth gets it wrong. At least it did when I first heard about the guy. We were told, perhaps like you, that he was so enamoured of himself that he actually tried to command the tide to stop in full spate — a lesson in how egos can get inflated, we were to understand. Fact is, he was well aware of his limited authority and either did this bit of theatre to demonstrate that kings were nothing compared to the might of God or to prove to his courtiers that they had a foolish notion of how powerful he was.
This mushing of an originally sharp meaning happens all the time. Take the expression "the lion's share." As it's used now, it means the largest portion — as befits what's due to the king of the beasts. It once meant something more biting, which is to say not merely the largest portion but the whole damn thing. The irony in the use of "share" to really mean the whole is now gone. (If you find yourself needing to request the whole as your due, you might do as an uncle of mine did when offered pie and say, "Just cut it in half and I'll take the two outside pieces.")
A similar thing happened with the expression "carrot and stick." Now it's used as if it described some B.F. Skinner, modifying behaviour with reward and punishment, depending on the need of the moment. But originally the setup was much more interesting, giving us a carrot tied to the end of a stick which kept it permanently in a donkey's view and equally permanently out of reach, no matter how much the poor beast trotted towards it — a much sharper linguistic tool, I'd say, to describe a great deal of our current, or anyone's, economic system. (As the White Queen said to Alice, "Two pence a week, and jam every other day," which, she subsequently explained to mean "[J]am to-morrow and jam yesterday – but never jam to-day.")
Change, however, is inevitable, in English as in anything. One of my favourite illustrations came about when we switched (more or less) to the metric system. When miles morphed into meters, or, rather, kilometers (which we're still not sure how to pronounce), one gentleman complained scornfully in the letters section of the Globe and Mail that now we'd have to say, "Give them an inch and they'll take a kilometer," and wouldn't that be an ugly thing. What the letter writer hadn't bothered to find out was that the original expression wasn't about "taking a mile" instead of an inch but about the much more euphonious — and realistic — "ell," a measure (roughly a cubit) that had passed out of use many years before.
So I do my best to let go of the old ways, but only after the struggle is hopeless and a "forlorn hope." And you're like that too, you closet conservative — when it comes to the vast majority of what you say or write. Otherwise, you'd wake up one morning and say "Impenatrability!"
'But "glory" doesn't mean "a nice knock-down argument",' Alice objected.
'When I use a word,' Humpty Dumpty said, in rather a scornful tone, 'it means just what I choose it to mean — neither more nor less.'
'The question is,' said Alice, 'whether you can make words mean so many different things.'
'The question is,' said Humpty Dumpty, 'which is to be master — that's all.'
Alice was too much puzzled to say anything; so after a minute Humpty Dumpty began again. 'They've a temper, some of them — particularly verbs: they're the proudest — adjectives you can do anything with, but not verbs — however, I can manage the whole lot of them! Impenetrability! That's what I say!'