So you want to keep unused images on you server?

Man, are you petulant, sometimes.
The fact that I don't want to use an attached image in one article, does not mean I won't use it in another.
Having to re upload every time I remove an image from an article is a pain in the buttocks!
Or do you really think we are so stupid and sloppy that we cannot delete an image that we don't use anymore?
Or cannot decide between un-link and trash?

..or you could just accept the question litterally. A simple"yes" answer would have been ok.

And indeed many users don't understand/don't care to know about the difference between unlink and delete. When they remove the image they remove it and don't think about it any more.

Many users also want the smallest possible backups.

I actually raised this issue before. http://forums.b2evolution.net/6-7-3-unlink-icon-in-post-edit
Sometimes I edit via my iPad and sometimes I do touch the wrong link by mistake, so linking by mistake is more common than you think. In fact I had to reupload several times as a result. I must say it is rather more an inconvenience than having to delete it later. Perhaps give the user the choice to add this button in the back office?

A simple yes to the wrong question.
If I have an image on the server, it is there for the purpose of using it.
Otherwise it would not be on the server in the first place.
Ditto @achillis

@achillis When you link by mistake; what where you trying to hit instead? The line above/below? (I am asking to see if better positioning of icons/buttons can avoid tap errors)

@gerardp I understand your view. There are hundreds of thousands of other users too. Some of them don't have images on the server for the purpose of using them forever. They use them for some time and one day they decide to remove it from the post, either because it's obsolete or because they have an updated version or because they actually uploaded the wrong version. And they don't plan to use that file again.

• Already in the current release: If you link the file to a second post before deleting, then you actually get an unlink icon.
• For v6.8, what's better?:
  • Have 2 icons, one for unlink, one for delete (will take more space in the list);
  • Have a dialog in case on delete (which already exist) which would offer an additional option like "Unlink only; don't delete"

@fplanque
Indeed, when an image is linked more than once, it can be unlinked. That's good.
My philosophy would be to keep it stupid simple. There is - even now - space in the "Actions" menu; so unlink - trash seems the simplest.
Adding a dialogue to the confirm trash might be confusing, because that's not what we're used to when we delete. On most systems we just get a confirmation dialogue, right?