Just more burden for interop between all kind1 clients, every new thing makes it harder to build a feature complete microblogging client. 

In this case it doesn’t really break anything by not implementing it so it’s not too bad.

To do it properly would require a decent amount of UI work. I would want the ability to show that it was edited and show the original version.

I’m not philosophically against it. it is one of the most requested features next to deletion. Entire groups of people have left once they discovered there was no delete or edit, so may have to do it eventually.