Comment 6 for bug 738710

That would inconvenience the minority of users who asked for the other options; perhaps they are common to them. It would be thus a usability downgrade for them compared to the right-click menu available to them in 10.10.

Here is my dream solution:
In preferences, have a "Quicklist" tab if it is relevant to be shown. In there, display a table of two columns - one of checkmarks, and the other of a quicklist name. Enabling a row will have it show in the unity quicklist, disabling it will grey it out and not show it.

We can set a sensible default of 4 most common to be available there (in my opinion - redo, capture desktop, capture window, capture web) and the rest will be available for configuration. That way, both the majority and minorities will be satisfied.