There should be a recycle bin, but the bigger issue is people being irresponsible with their own data. A recycle bin will not be a cure (although it should exist).
When you delete a file in Chrome OS there is a lightbox-style alert asking for confirmation. If you manage to accidentally hit the delete button, then confirm it, you've now selected to delete the file twice. To do that on accident is quite a trick. Compare this to other operating systems where you can delete a file in one click or drag/drop to the recycle bin and then easily clear the entire bin on accident. In that paradigm the same people are wiping out their own data. There was another thread on here about people wiping out their entire Gmail--think about that, how many clicks it would take to clear your entire Gmail, which has a Trash. And yet people do it. This is really more of a matter of education that people need to pay attention when they hit the delete key on a computer. Google and Microsoft cannot save people from themselves.
If we wanted to talk about a cool feature: if we get Google Drive integration, and everything on the shelf can be synced to a Drive folder, perhaps we could have a Timeline-esque cloud based solution. That would be awesome, and would go a long ways towards saving people from themselves.