How many people routinely have the add-ins tab selected when using Outlook? Answer; no-one.
How much easier would it be to access the Act! integration features from a right-click on an email than from the add-ins tab which takes an additional click to get here plus an another click to return to the Home tab.
Third-party Outlook integration add-ons have demonstrated that this is, by far, the best way to access this functionality.