There's a difference between a tool having flaws and it being evil. FB, Twitter, etc all have major flaws. That's why they can get abused or used for nefarious purposes, but there's also plenty of virtuous uses as well. Otherwise you could just saw the internet is evil too. After all, there's email spam, there's horrible content on the web, etc.
It is up to software developers/companies to come up with better tools and to address the flaws (I think decentralization would address plenty of issues). It is up to users to choose the good ones and to use them properly. Education (not just tech-savvy, but also just plain literacy and cultural knowledge) would also go a long way in helping users.