I got this question in my head a while back when I was reading this related post.
https://steemit.com/funny/@h725/how-can-anybody-go-below-25
It just seemed kinda funny because I've never experienced anything related to downvotes or losing reputation.
I decided to study lost reputation a little more closely.
I found that there is a full reputation ranking at steemwhales.com.
This is the last page.
Apparently the lowest reputation score on quora belongs to "Wang".
His account is worth several hundred thousand dollars.
He was one of the first Steemians, joining in April 2016.
Upon closer inspection, it appears "Wang" is a bot.
@Wang would comment beginner tips about how to use Steemit in the introduceyourself section.
But mods felt it was spam, so they would always downvote him.
Eventually the bot controller decided to pull the bot, so they stopped the program and posted a farewell message in introduceyourself that can be found here.
https://steemit.com/introduceyourself/@wang/farewell-so-much-hate
Apparently, @Wang still upvotes posts on occasion.
Edit: The original reason why I tagged this #introduceyourself is because @Wang posted his most notable post in introduceyourself. I didn't realize this might be considered my own introduction, and I might decide to actually introduce myself in the future. Nonetheless, I'm grateful for the support of Steemians in the comments who have welcomed me in the comments.