I try very hard not to make mistakes when writing/typing and continue to reach for a dictionary for those tricky words. If I'm not sure of a meaning, again, I will reach for a dictionary (this seems to be a lost "art".)
I constantly see horrific spellings when out and about or conducting business. I usually will point them out....I mean, would you use a lawyer or accountant if their advertising was full of errors?
My kids were taught from an early age, you don't use a word unless you can spell it and you know what it means.
What we do have to remember though, places like this site and others, English is a second language for many people. As well, there are many among us who have not had the opportunity of a good education. My husband had very little formal schooling, English is his second language and he does find English incredibly difficult to write. He is a very gifted man and is valued at his workplace for being their best troubleshooter and problem-solver. His math skills are awesome and he was a huge help to the boys when doing higher math studies at University. So, while some of us word enthusiasts and literature buffs can be a tad pedantic....there are a lot of other skills to be learned from our less "wordy" friends.:)