“…among the ranks of the “Grammar Rules We Knowingly Break Because Those Rules Are Stupid”, the long-standing edict against “hopefully” has long held a place at the top.”
The AP Style Guide “Grammar Regulators” (a term I adore for its utter pointlessness) have admitted the adverb “hopefully” to the list of allowable Disjuncts. Disjuncts (AKA “sentence adverbs”) are “set-the-mood” words that modify the entire sentence. They’re also incredibly useful! Take a look at these examples:
“Myrtle sang the entire Gilbert and Sullivan Songbook.”
“Apparently, Myrtle sang the entire Gilbert and Sullivan Songbook.”
“Fortunately, Myrtle sang the entire Gilbert and Sullivan Songbook.”
“Regrettably, Myrtle sang the entire Gilbert and Sullivan Songbook.”
And now we know quite a bit about Myrtle, for good or ill.
Style guides are always the last to change because they are reflective. The purpose of a style guide is to give editors something to point at when someone disagrees with them: “Take that up with the MLA Handbook, my friend!”
Usage guides are a bit more opinionated. Some are downright liberal (cough, cough, Merriam-Webster, cough) while others take a hard line about The Rules.
Unfortunately, many educators use style and usage guides as if they were grammar itself: these are the rules, learn them, live them, love them.
Here’s a little secret, though: grammar isn’t absolute. God did not create light, earth, and grammar. Grammar is a set of expectations, that’s all, and expectations change over time. Fortunately, we make changes rationally, occasionally (admittedly) thoughtlessly, but, interestingly, generally successfully. Hopefully.