English is dead, long live English

As some of you might know, I originally trained as a teacher . . . a highschool English teacher to be exact. I never thought of myself as a grammar police type of person; that is until now. Before I go into my rant I would like to placate a particular argument that may be used against this aforementioned rant. All languages do, indeed, evolve and mutate (for want of a better word) into newer forms as new linguistic elements are introduced from new population groups. I accept that as a given. I do not accept what I call "language-laziness" or "I-can't-be-bothered" syndrome. This apathy is rather contagious and has become increasingly prevalent with each passing year. My main sticking point for today is the use of the grammarl and syntax structure known in colloquial terms as "apostrophe es" or ___ 's ____ .
So now, do you remember what you were told way back in grammar school about this particular structure? It has one main function:
to show ownership
This funky little doo-dad is tacked on at the end of a noun, noun phrase, or other noun-like structure to show that the particular noun has ownership of the following subject. For instance:
This is John's bicycle.
The __'s__ lets us know that John is in ownership of the bicycle.
But, as with all things in English, there is an exception to the rule. If this thingy is tacked onto a third-person noun or nearly anything else other than a first or second person noun then it changes its meaning to: hey, I represent something that's been dropped off and in this case it happens to be an "i" as in the word "is."
Case in point: it's -> it is (not ownership!)
Case #2 in point: there's -> there is (definitely not ownership, just imagine the word "there" owning something)

So, with that boring stuff in mind lets get to an example seen in an advertisement:
(names of proper nouns have been changed to keep from embarrassing such tender sensibilities)

"Coffee Company's new line of tasty drinks are now on your grocer's shelves! Try new coffees, mocha's and cappucino's . . .!"

Uh huh, see the problem? There's a plethora of __'s___ in the advert. and most of them are used properly. But, oh dear reader, what the hell does the mocha and cappucino have possession of? Do these drinks suddenly possess the drinker as soon as they are consumed?

I think not.