Why are you even encouraging any one to click a link in any email?! Perhaps you’ve never heard of how dangerous that is? For exactly the reasons you say it is convenient for the user, it is even more “convenient” for SPAMmers/information gathers/hackers/etc. So, please stop encouraging “developers” from using tracking info or even including links in email messages. Period. 
When I want to unsub, it is stupidly obvious that I should return to the site where I subscribed. Hopefully that site’s name will be displayed in plain, non-linked text.