Comment 20 for bug 1265192

Even if you have a single boot system, "reinstall ubuntu" or "replace windows" silently erases all partitions on the hard drive.

@Dimitri
The warning does not unambiguously specify that ALL PARTITIONS including non-OS partitions will be deleted. (e.g. a D: drive on windows or a separate /home partition that was used by the previous linux install)

The fallout from this is going to be truly ugly, and is just growing everyday that the new LTS is out with this bug and people attempt to try out ubuntu for the first time / reinstall their previous OS.

At a bare minimum, we need to remove the reinstall option entirely. Alternatively it can be renamed to "erase and use entire drive". (This used to be an option that used to be present before)