Could of? Would of? Should of?

Question: why is it that so many people do not understand the subtly blatant art of contractions?

I've never really been one to heed the shrill cry of grammar harpies; frankly, I couldn't care less about the use of contractions in everyday speech. Or writing, for that matter. But for the love of crap, people! You've got to know what they mean! It's not like these are particularly challenging concepts. The 'it's's and 'what's's and 'must've's of the world are pretty straight forward. Most people understand these contractions quite well, and yet a large portion of this most is at a complete loss when it comes to translating meaning into text. So here, kiddies, is a simple grammar lesson from Sarah, honourary harpy:

've >< of; 've = have. HAVE. For the love of crap, HAVE!

Thank you, and good day.