In short for importing, rendering and exporting audio, art or video in these programs.
it's simple enough to just to a do a custom install of Quicktime as the issues are in the player and not specifically the codec.
I also use Adobe CS 6 and Quicktime is not required for Photoshop.
35 years as a graphic designer for print, web and video.
Not saying I'm an authority on the subject .... but I do know what is required to use these applications
:-)