There are various technical reasons why the installation location of file on hard disk drives should be controllable by the user. Many systems are configured with a small, fast SSD for the "system drive" and use multi-TB rotating drives for samples, music, and video work.  Different backup strategies also make it desirable to keep the system drive smaller.
 
After upgrading to Sonar Platinum, I measured 6.2 Gbytes of files were installed to my C: Drive. This was after selecting alternate drives at every opportunity that was offered.  The actual Sonar executables and support files are a few hundred MB - most of that space is samples and other content.  Please see my related post here http://forum.cakewalk.com/FindPost/3199309
 
The installers need to be improved to limit installation on the C:\Program Files path to actual "Program Files". The location for installing samples and other supporting data should be user-configurable.