I saw the comments in that thread, chose to stay out of it. I avoid trouble like the plague (stay far away). But I'm glad that you, even though you feel you had valid points made (even if misunderstanding), realized the harshness of your words...sounded pretty hard. I think we all go through it occasionally, sometimes it is difficult to convey what you want to say to another without offending them or just sounding like a jerk. Done it myself for sure and sometimes I'd look back and say to myself, why did you post that, that was a bitchy thing to say.
I did that one time last year when I wrote a note to my store manager because I was upset about being scheduled for a time early in the morning and ended up standing there for an hour with no one else showing up to open the store so I could start working, to find out the one opening was schedule by her for a later time. My words were quite snotty. I had a very legitimate reason to be pissed off, but could have handled it differently. She as well, totally went berserk when she saw the letter I left. Made working there very strained, we didn't get along at all for months. Finally it just somehow mended itself not too long ago. But, after writing it, even while writing it, I knew it was a mistake, but felt it was too late to retract it. We were both very stubborn, neither of us ever apologized for our behaviors, but I think all is forgiven anyway. Thank goodness because some days she was so horrible to me I nearly walked out.