This is just a convention that used to be somewhat useful in the past. It doesn't mean anything any more.
In modern Windows versions, a program can specify several options to be displayed in the "Programs and Features" panel. The default is an uninstall option, but there can also be options for repairing and changing any individual components.
However, back in the olden days of Windows 95/98, you could manage installed programs from the "Add/Remove Programs" control panel, which only contained a single option, named 'Add/Remove'. If the uninstaller supported anything more than a simple removal, it had to ask the user itself with a dialog box. To avoid user confusion, some programs that didn't support any fancy options would state so by adding "(remove only)" to the program uninstall entry.
![Win98 Add Remove](../../I/static/images/4e794639024142add5522d37a33996b3b6efc935e032165f8ff0724316c3c5d8.png)
Some people simply got into the habit of doing this and therefore it persists to this day.
I was of the impression that this was to do with installers that don't use MSI to register the files, folders, etc. that they install. A program entry may appear in the programs and features section that has not used MSI and therefore windows cannot do a 'repair' because it doesn't know what to repair. – Matt Wilko – 2011-05-04T12:32:15.193