I dumped my Reddit account a few weeks ago. I'm sure I wasn't as prolific as many of you, but I had been on there a few years, made the front page with a self post, had several thousand comment karma and had almost 1000 link Karma. I just got sick of it, especially because -as another user here pointed out in his comment- one quick downvote a few seconds after a post could derail any conversation I started. What's more, it seemed like it was happening with increased regularity since Reddit hit the main stream.
Sure, some of my posts were just stupid fun, but there were other posts that I really thought about and hoped to discuss. Frankly it made me angry that a 14 year old somewhere could slam the door on an adult discussion they couldn't take the time to understand.
I still have a Reddit account, but since I quit I have never posted a single comment and I never will again. I also ensure that any upvote I give is balanced by a downvote. I especially downvote obvious troll reposts and stupid TILs about things any idiot should already know TIL water is wet!"