I upvoted it!!
Nice to see a comment receive more than the opening post. But it's rare, and as you said is a failure of reader engagement. People just like posts they think may go viral and provide low content replies.
As for the algorithm, it's tough to balance. The algorithm obviously has its positives, such as weeding out spam and rewarding those who sift through the endless content and like what is quality. But like you said, an additional payout algorithm that quadratically distributes payouts to commenters would help