If you've spent any amount of time on the forums in the past couple weeks you are probably also tired of seeing "I'm quitting due to X bug." Last I checked, there were 8 on the front page.
1. Very few of the bugs I've encountered or read about are truly game-breaking. Many are bugged quests or flash-points that you can skip and continue with your game experience. They may frustrate you, but you can skip them.
2. Another game I'm highly fond of, Skyrim, has plenty of bugs that might be considered game-breaking. Regardless of how many bugs I find, I'm still playing that game after a month and 80 hours plus into it. I see the bad, acknowledge it, petition for a fix, but keep going because I enjoy the overall experience I have with the game. Skyward Sword is the same way. In fact, there's a few bugs in that game that can ruin your save.
3. I've been around the mmo block (eq, launch for wow, swg, lotro, eq2, aion, rift, etc.), and quit games that had far more bugs than this one. While the bugs can frustrate and possibly accelerate my departure, it was never the reason I left.
If you're going to make an "I quit" post, which I know you will since the community is so sincerely interested in your reasons, please make sure you list the real reason you're going. Miss your 85 wow character? I've got those and completely understand. Over the "MMO experience?" I thought I was there, then I jumped into this game.
If you're only upset about bugs and don't actually cancel and let your subscription lapse, please just create an in-game ticket, petition the CS forums and move on to your next game.
This game is not perfect by a long shot, but I think saying it wasn't finished is unfair. What are the industry standards for a finished game? Have you carefully scrutinized this game compared to those? I remember losing my wow server at launch for weeks at a time. I play on fatman, so I've experienced the queue but nothing like wow's launch. I remember the truly game-breaking bugs at the launch of lotro and eq2.
TLDR version - Be honest about why you're quitting, and don't cite bugs. If you're not actually quitting and just want attention brought to the bugs that irritate you, file a ticket and start a thread on the CS forums.