Grimm's Law documents certain technical points of language evolution. It notes a general softening of consonants and a general blurring of distinctions over time. Latin 'pater' becomes English 'father'. The formerly different consonants 'bh' and 'b' become the same consonant 'b'. I speculate that some sort of generalized Grimm's law applies to many aspects of language and thinking, particularly technical language. I've noticed, over time, a general softening of edges and blurrings of distinctions. Here are some examples:
“Lie” and “lay.” People used to care about the difference. “I lie down on the couch” meant now, “I lay down on the couch” meant some time in the past, and “I lie the book on the table” was unsayable. I don't think anyone cares about the difference any more.
The short 'e' and the short 'a' are merging. Very young people, especially, pronounce “friends” as “frands” and “help” as “halp”, for instance. Even television talking heads are not careful about the distinction. Next time someone on the phone asks if you have a “pen” handy, you might reply with a question: “cast-iron or aluminum with teflon?”
“It's” and “Its” used to be different. My mnemonic was “It's lost its apostrophe.” However, even in very formal writing, I see “it's” used for the possessive, something that used to be a single-point of failure in a school essay. If you wrote “... format it's hard drive ...” you'd get an “F” on your paper, no matter what else was in it.
Singular and plural used to be different. “Every user opens their inbox” was a train wreck, “user” being singular and “their” being plural. Hypersensitivity to sexism, however, has forced a blurring of this distinction, since no one wants to write “Every user opens his inbox“ -- that's annoying, “Every user opens his or her inbox” -- that's awkward, or “Every user opens her inbox” -- that's distracting. I don't know why no one notices that “Every user opens the inbox” would avoid the train wreck.
“Which” and “that” used to be different. One used to require a comma before “which”. The following two sentences used to have slightly different shades of meaning: “The book, which is on the table, is mine” and “The book that is on the table is mine.” The first sentance simply noted a peripheral fact about the book -- the fact that it's on the table. The second sentence noted a critical distinction between the book on the table and every other book. “The book which is on the table is mine“ would get you an “F“ on your school essay. No one cares about this distinction any more.
Hyphens used to be important. A “first-class object” made it clear that the object was first-class, whereas a “first class object” blurs the distinction with the very first object of a class. Used to be “first class object” would get you an “F” on your paper, but no one seems to notice the blurring of distinctions afforded by forgetting the hyphen.
I could go on, but suffice it to say that the overall, slow-but-steady blurring of distinctions over time results in a kind of global loss of precision in language. I think it's an entropic effect. Nevertheless, the loss of precision means that we tend to need more words to make our point. Papers get longer AND less precise. So, here's the value judgment: I don't think this is a great trend. I think careful thinkers -- those concerned with hygiene of thought -- will notice these trends and try to swim upstream against the driving current of entropy.