It sounds like it's necessary from this Adobe technote: http://helpx.adobe.com/x-productkb/global/known-issues-mac-os-10.html
"If the Java Runtime isn't installed, the following issues can occur in Adobe applications:
- Features are missing or behave improperly
- The software doesn't start
- Prompts to install Java Runtime occur
- Applications hang or quit"
Here is an article on current security issues with Java. The danger isn't in running applications that require Java. It's in allowing your web browser to have Java turned on:
I am also looking for an official Adobe note on the same thing in the context of only having Java SE 7 installed, while Adobe Photoshop won't run and keeps asking to install the old Java SE 6 which is no longer supported for security reasons. You can see my thread on this issue, where I have gatthered all the information I can find on the Photoshop Problem in OS X 10.7.5 and OS X 10.8.