"From my experience, about 95% of english speaking people (even educated people) employ this grammar"

Ninety-five percent, eh?

Then perhaps it's correct.

Surely not. Doesn't a sentence require a subject and a verb?

Then how do you explain your "Surely not." above?

Sure.

"I think this goes right along with improper uses of 'your' and 'there.' It boils down to laziness of children in school."

Nonsense. When someone writes "your" for "you're", it's simply a spelling mistake based on their uncertainty with homophonous words. Being a poor speller is hardly an indication of laziness.

Given the eccentricities of our English spelling system, mistakes like this are not surprising.

Our written language almost invites such misspellings.

"I am making our x-mas cards and our last name is Gonzalez. How do I write it - Gonzalez' or Gonzalez's?"

You could write "The Gonzalezs" but that would look odd.

Avoid this mess by writing "The Gonzalez Family".

"We have already established what is correct."

Quite the contrary.

We have established no such thing.

Speaking as a Canadian, I do not wish to be referred to as an American.

But I am also not bothered in the least that term is used by folks in the US to describe themselves.

"Correct use of the language has nothing to do with any kind of "prescriptivist bible'."

Of course, that would depend on what you mean by "correct".

"I revel in the fact that English is governed by 'Common Usage'"

Well of course, the truth is that all languages are - no matter what some august member of the Académie française or the Asociación de Academias de la Lengua Española might wish to think.

"Every verb in Engish has a subjunctive tense."

The subjunctive is a mood, not a tense.

And while most English verbs have at least one distinctly subjunctive verb form (the uninflected base form of the verb in the third person singular), many of those tricky modal verbs don't (they represent an entirely more cumbersome argument. For example, is "would" a subjunctive form of "will"?). We could open up another argument here about the conditional versus the subjunctive.

Because the presence of subjunctive verb forms in English is so limited, there's a tendency to overengineer the grammar. That Wikipedia link provides what I consider to be a vastly overcomplicated table on the English subjunctive.

A BIG part of our problem is that our approach to English grammar still tends to rely on hammering a square peg into the round hole of a Latin structural model; a model that is not always appropriate or even useful.