Frasier getting the grammar wrong?!

This was in dreadful season 9 when Lori Kirkland was the head writer..even Kelsey Grammar publicly apologised for the declining writing in the last few seasons.

I asked AI: Is "It's just you and I now" grammatically correct?

Following is the answer:

No, "It's just you and I now" is not grammatically correct.

The correct phrase is "It's just you and me now."

Here's why:

"You" and "I" are pronouns. "You" is the second-person pronoun (used for the person being spoken to), and "I" is the first-person pronoun (used by the speaker to refer to themself).
In this sentence, "you" and "I" are the subject of the sentence, along with "it" (though "it" is impersonal). The subject pronouns are the ones performing the action (existing alone in this case).
"Me" is the object pronoun, used when "you" and "I" are receiving the action.

An easy trick to remember which one to use is to take out "you and" and see if the sentence sounds natural with just "I" or "me." In this case, "It's just me now" sounds grammatically correct, so "me" is the right pronoun to use.

Interesting point considering "you and I" is generally (incorrectly) considered "proper grammar" when used as objective pronouns. It's viewed as grammatical overcorrection, when people try to sound smart but don't understand that they're actually wrong.

I remember seeing it first in "Facts of Life," an old sitcom, where "she and I" as objective forms was commended as proper grammar

Obama uses it all the time: "They were very gracious to Michelle and I." Drives me batshit

So it makes sense that Frasier would be the type to correct the overcorrection. But you're right that Martin was NOT incorrect in this sense.

Now, there ARE arguments to be made that "is" can be a transitive verb in certain contexts, e.g., "woe is me." In that case, "is" actually means "is unto."

So I suppose "it's just you and me now" is actually "it's just down to you and me now" which WOULD be correct (and yes I realize the writers didn't come CLOSE to thinking about this hard)

Even if that were the case, it wouldn't be cause for Frasier to correct Martin -- at best, both versions would be acceptable

One thing I noticed about "Big Bang Theory" along those lines is that they were very careful to make Sheldon's annoying corrections actually correct in every case I can think of. I understand they also took pains to ensure the accuracy of the "science gobbledygook" in that show whether spoken or written on the whiteboards

clearly not the case in "Frasier"