Speaking Correctly

It's amazing to me how people take the language they speak for granted. God intended language to be used for communication and it is an extremely important means whereby to do that. What I don't understand is why there is this prevailing attitude of "I can say whatever I want and it doesn't matter if it's the correct word or phrasing because the people that know me will understand me and I don't care if any one else does."

I do understand that there are colloquialisms, dialects, and other differences in a common language that will cause a few misunderstandings (most of them funny!), but the intentional disregard for the correct word or grammar drives me absolutely insane. Why would anyone not care about what they are trying to say or just use any old word that sounds good without thinking about the meaning?

I certainly don't expect 10-syllable words from everyone and in fact, would rather have someone use simple words correctly than to use a 50 cent word incorrectly. I can remember working with a guy who was telling me that I would rather dissect orgasms than work on cars. Orgasms??? Of course, I laughed out loud and knew he meant organisms. Instead of using the 50 cent word while trying to impress someone, he should have used something like animals or creatures. The meaning would have been the same and he wouldn't have ended up looking like a buffoon.

Writing is also as bad. I don't understand the common misuse of certain English words in writing. For example, does anyone know the difference between their, there, and they're? What about whose and who's? These everyday words should never be a problem but they are misused everyday. For those of you not sure which is which, allow me to differentiate.

Their--possessive pronoun. Example: Their dog.
There--locational adverb. Example: Place it over there.

They're--contraction of "they are". Example: They're cute.

Whose--possessive adjective. Example: Whose book is this?
Who's--contraction of "who is". Example: Who's going to the store?

Please be careful of your speech and writing. Think about what you're going to say before it comes out of your mouth. Simple is better than sounding downright stupid.