I’m quite comfortable saying everything my handle says in real life with my real face and my real name. 
The internet is a very large public square and I don’t trust everyone in the whole world. I can build a reputation with my nym and grow a community of friends and trust. Then I can invite certain people in and exclude others from my real life. This isn’t hiding this is sensible and secure. 
I wear a digital outfit to cover the parts of myself that I don’t want to share with everyone. This isn’t fear it’s common sense. 

 This is actually the best objection to my post I’ve read today — and there have been many. 

There are a lot of psychos out there, and it’s why I’ll put pictures of my dog on social media, but never my daughter. 

But there’s a difference between social media activity of making friends and socializing vs voicing your views in the public square. With the former what you say makes a ton of sense. With the latter, I think it makes a big difference for things to come from a person for the reasons I said in the post.