Grammar and Spelling- Good Lord!

OK- I just have to talk about this one because it is driving me crazy and it's getting worse by the week.

I cannot figure out why people these days can't seem to get the possessives and contractions correct.  There is a huge difference between your and you're, between it's and its, between there and their and between numerous other homonyms.  I think that's what they're called.  Hey! there's another one!

I see a lot of stuff written by a lot of smart people that gets this wrong all the time.  And I see my daughter do it on Facebook and emails (her typing is atrocious and she doesn't care, but typos are a different story.  These things are not typos.)  My husband does it on emails.  he says it's a typo, but it's not.  "Adn" is a typo.  I make it all the the time.  "To" instead of "too" is not usually a typo.  I see it on documents at work as well.  Another common one I see at work is the possessive apostrophe in the wrong place- "patient's" when it's plural and "patients' " is correct.

Are the schools not teaching this properly anymore?  Do people just not care?  When I see these kind of mistakes, I think it makes people look ignorant.  If you know what it's supposed to be, then do it right.  What is the world coming to?  Am I doomed to see this carelessness more and more and be driven even more crazy as the years pass?  Should I just let it go?  What?!?!

What is your pet grammar peeve?  I have WAY more than this one, but this is the one that has been driving me crazy lately.