Okay, I'm sure my grammar, tense, and sentence and paragraph structure suck most of the time, but I do my best with the bits I remember. English is a very ambiguous language, with completely archaic and arbitrary rules. But that's because it just steals everything from other languages, which I kind of dig actually. I've heard it said that "We don't just borrow words; on occasion, English has pursued other languages down alleyways to beat them unconscious and rifle their pockets for new vocabulary." Language evolves or it dies, just like every other living thing. While some usages do bother me, such as using literally to mean figuratively, I try to appreciate the beauty of a language that adapts itself to changes in time and circumstance.
Eloquence and elegance in the use of language is something I greatly admire and aspire to, and I get quite happy when I find a new word I like. Both of which are probably really sad, and I can only guess the extent to which my writing comes across as both pretentious and ignorant at the same time. But I like cool words so I try to use them to deliver the full meaning and nuance of the thought I'm trying to convey. Earlier this year I stumbled across the word "transmundane", I was happy I found that one

As far as correcting other people's mistakes, I generally try not to as I don't want to embarrass or insult anyone whose intent was not malicious. Personally, I would prefer for people to correct me so that I can try to improve myself, though I see how it can be rude and condescending to point out where someone else is wrong.
I don't judge for any mistakes I encounter except in two cases - 1. When they're correcting someone else for something, grammar related or not, and 2. if it's in a publication of some sort. If you're publishing something and you don't bother to find and fix your mistakes, or at least get someone else to point them out to you, then why should I take what you're writing seriously? You certainly don't. Forum posts, personal blogs, and other informal writings excepted.
Also, I'm kind of embarrassed to post anything on this subject, as I guarantee that there are tons of mistakes. And I know it's overly verbose, sorry