MS Word SUCKS!

In oh-so-many ways, of course, but I just need to vent about one in particular.

• "Its" is a possessive, meaning that the object being discussed belongs to the subject It.
• "It's" is a contraction for "it is".
  

Why, then, does Word always do that little green grammatical underline when I use "It's"?? As in, "I've attached blah-blah-blah. It's labeled Chapter 12." Right-clicking on the underline produces the demand that I change "It's" to "Its" which is simply, damn it, WRONG! Not that this is the only grammar error contained in that most rancor-raising of software programs, but it is (IT'S!!) the one that's irking me most at the moment.

Whose bright idea was it to let computer programmers be the arbiters of grammar??

Ok, I feel better now. Mostly, at least.