I don't understand the fear of not being able to delete notes. 

The Internet is just amplifying the reach of your speech. You can't delete what is posted just like you can't unspeak what you have spoken. 

Yes, now there is a permanent record of what you say and everyone can see it. It is the price, and the beauty, of having the Internet megaphone. 

So use it wisely. Think twice before you post.

The inability to delete has the potential to make the Internet a better place. To get rid of all the bullshit that goes around elsewhere in centralized apps. 

Also, in the early years of the Internet I was told that sharing something on the Internet was like peeing in the swimming pool: once it's out, you can't take it back. I drill this into my kids EVERY day.