Apostrophes appalled at apostrophe’s misuse

I saw this on Facebook this morning. Note the “couple’s” in the description and “couples” in the link headline. Are they both correct?

Let’s look at what apostrophes are used for. Yes, let’s. “Let’s” in this usage is a contraction for “let us.” The apostrophe lets us know this is a contraction—two words are put together, and the apostrophe tells us there are letters missing from the original word two words.

Another use of apostsrophes is for possessive nouns, such as the dog’s bone or the team’s victory. Something belongs to something else.

So let us take a critical look at the post. Is “couple’s” used as a contraction? Is it short for “couple is”? “This was an interesting article on what can cause couple is to fall apart.” No, definitely not a contraction.

Is this a possessive noun? Does the headline tell use that the couple owns something? Does the couple own “to fall apart”? Again, no, definitely not a possessive.

Written another way, the post says, “This was an interesting article on what can cause more than one couple to fall apart.” Therefore, the word should be the plural form of couple. Couples.
“This was an interesting article on what can cause couples to fall apart.”

What about the use of “couples” in the link? Is it correct? I bet you can figure it out.

P.S. By the way, the article is excellent.