Just my two cents worth.

An unsophisticated newbie would certainly consider this thread to be a legitimate bug report. I won't argue otherwise. 

You at Ubuntu are not alone in assuming too much knowledge on the part of newbies and even many experienced users. 

I come from a different background. I have always done multi-OS/multi-boot installations, from DOS to Windows 95/98/XP/7 and 8 (previews and 8.0). And now Ubuntu Linux from 13.04 to 14.04. I have never accidentally wiped out any installed OS. Lost OS access a few times, but that could be fixed later (with difficulty).  Read on to find out why I have been so "lucky".  

I have NEVER let an OS installer, disk or download or upgrade adviser, use ANY default installation routine. These are notorious for overwriting the entire hard drive, or even multiple internal drives, formatting them and then making the OS installation take over the entire disk or disks. What this thread describes is nowhere near unique to Ubuntu 14.04.

NO ONE makes it clear on their install disk selection screens, not even Windows System Builder Editions, that the failure to select "Custom partitioning" or a "Custom Installation" will result in the ENTIRE hard drive being reformatted. It is assumed that anyone sophisticated enough to be doing their own OS install from a disk (or a download) will know enough to choose "Custom" for ANY dual- or multi-boot or Repair or Upgrade In-Place installation. 

My precautions are to make Full Image Backups of all contents of the drive which can be backed up, burn disks of the Windows Restore Partition, and to use gParted or MiniTool to make my own partitions before running any OS upgrade or fresh installation.

And other precautions, but everyone should see my point. 

Not everyone makes such a study of partitioning and OS installation before using an install disk for the first time (or as an upgrade). 

While most Upgrade Advisors do not reformat before upgrading, most full install disks do exactly that to the entire hard drive.  Maybe not every Upgrade Install Disk behaves as I describe, but all Full Versions. Nearly every OS I've installed behaves the same way. 

And, maddeningly enough, without so much as a screen saying, 
"You are about to wipe out all data on this entire drive. Proceed? ...  Are you SURE?" (If Not Sure, offer the Custom Partitioning installation and be prepared for screams of agony from newbies. This safeguard will not necessarily save those installing into VMs, but they should know better than to do a Default Install anyway.)  

What is really needed, is for anyone attempting to install Ubuntu to find on some prominently labeled Web Page, all the warnings in this thread, in BOLD CAPS.  All Ubuntu installation instructions should bear BOLD CAPS warnings about the default installation tending to WIPE OUT the entire disk -- ALL partitions. Otherwise, users should be instructed to select CUSTOM partitioning and installation options.  

(A side-note: GRUB2 is now by default another source of issues, as it ALWAYS installs into the MBR, and takes over Boot Manager duties for all installed OSes. There have been many complaints about this inflexibility. Again, some folks will not know this before installing Ubuntu.) 

A really strong warning might at least make new users and experienced users alike, think about what we are doing and plan things out before installing Ubuntu into a system with any pre-existing OS installation. 

Sorry about going on at length and with so many CAPS, but I thought some of the complaints in this thread needed special emphasis. No malice intended on my part toward anyone here.