Comment 2 for bug 214174

This file is a link and does not have permissions just like every other .desktop file in Ubuntu. Notice that .desktop files do not have an "Open With" tab either.

The package desktop-file-utils takes care of creating these. If you look into one of these .desktop files, you will see that they are simply a link reference. This is an entry which is handled differently then other files in a desktop environment such as gnome & kde. When we examine the file we see it is an entry in a database.

[Desktop Entry]
Version=1.0
Encoding=UTF-8
Name=Link to Bug #214174 in Ubuntu: “Link - Properties - Permissions, bad info? ”
Type=Link
URL=https://bugs.edge.launchpad.net/ubuntu/+bug/214174
Icon=gnome-fs-bookmark

And when you open the file, you are blocked from opening it with a text editor (unless you do it command line). All this is intentional action for this type of .desktop file.