smart!
I can't believe I've been downed because I found something smart.
Your first comment expressed very little. It would have been better to simply upvote the thread; saying "smart" or "I agree" or "good idea" tells us nothing more than your vote would have. It makes for boring reading, and as such, it gets downvoted as a form of discouragement.
Complaining about downvotes makes for even more boring reading. Instead of complaining, learn from the experience. If you want to express "I agree" or "good idea", just click the little up arrow. Only post a comment if you have something substantial to say.