I know my spelling / grammar aren't up to many peoples standards, but I had other people clean things up.
Good. I don't want to be an asshole about it. Bad spelling/grammar aren't moral failings; they have practical effects that can usually be eliminated with some decent proof reading. As I note, there's no obligation upon anyone to give that kind of attention to a Slashdot post. Nor do I claim complete perfection in this area on my own part.
I wish you could see your post through my eyes though - it's almost physically jarring.
I'm sorry but many really good engineers can't write.
I'm not sure about the "many". I've noticed a strong correlation between "good spelling/writing" and "good engineer" But certainly some good engineers really can't write and you're clearly a good engineer. I don't think that's in question.
But you're not trying to be just a good engineer. You're trying to be a good businessman too. You obviously have some talent for business - your successes even where partial show that - but I wonder if some of the problems you encounter actually arise from deficient soft-skills akin to writing?
This post in the meta-discussion on Hacker News might be insightful.
Good luck with your future endeavours; it certainly sounds like you've earned it!