why does quicken keep adding an icon to my home screen when i log out

I suspect you are accessing the data file in your desktop folder.  Quicken saves files within the same folder as the data file.  These include OFX log and Sync log data and Backup, Validate, and INET folders.   If you wish to avoid seeing these appear on your desktop, I suggest you relocate these data files and folders to another folder on your internal drive.  Typically, the data files are maintained in a Quicken folder in the Documents folder.