Disclaimer - I Don't "Like" Facebook
I'm no fan of Facebook and essentially have a dormant account with relatives as friends and login to my account every few weeks or so and don't post to it.
Evil Geniuses at Facebook
Say what you will about Facebook, they aren't dumb, in fact they are brilliant. For years people have been clamoring for a dislike button but they haven't budged. I can only speculate as to why, but looking to what is happening here at steemit.com I see a pretty compelling reason why they don't have one. Dislike, downvoting, etc. whatever the motivation only creates negative energy. Having unequal downvoting powers has created serious negative energy here.
What About Reddit?
Yes, people on reddit can upvote and downvote content but people with high karma have an equal downvote power as those with low karma. I don't think this is by accident.
We Must Fight Spam and Copy/Paste Content!!!
An argument has been made that the steemit.com brand, platform, etc. must be protected from spammers, copyright violators, etc. and an important tool is the downvote hammer. I think this is a poor argument because it is pie in the sky thinking that steemit.com can even come close to eliminate the above behavior. As time goes on it will only get worse. Will it hurts it's credibility? Hardly. Think of Wordpress.com, Tumblr, Blogspot. I dare say that 50% of those platforms have original content and the rest is either dormant or spam/copy and paste content. Google gives each and every one of those plenty of love.
Giving Power To The Psychic Vampires
No doubt many people use their downvotes judicially but many are just Psychic Vampires:
A psychic vampire is a mythological creature said to feed off the "life force" of other living creatures.
https://en.wikipedia.org/wiki/Psychic_vampire
Referring back to our evil genius Facebook friends, perhaps they know that keeping the site with thumbs ups and positive energy it is better than giving a few honest well meaning users (and some psychic vampires) a chance to give a thumbs down and alienate users. Everybody wants to feel welcome, nobody wants to be told they've done something wrong.