It isn’t, even it if it seems like it. When a user logs work with Tempo, the Tempo Timesheets plugin updates JIRA’s time spent field on the issue, as many Reports, functionalities and more are relying on this field. This also happens whenever a user edits or deletes a worklog. Tempo is now residing in it's own system, and using it's own database, by informing JIRA which user created a Worklog, we may be breaking the View All Worklog permission - as once this information is within JIRA, we can't protect it anymore, and JIRA will display the information in various places. We must not break our permissions when sending information out to JIRA. For this reason is the Tempo Timesheets plugin that updates the JIRA's time spent field, without disclosing any specific information.
When the JIRA's time spent field is being updated by Tempo, JIRA sends a notification to users according to the notification scheme. If you do not want to be notified, please disable the "Work logged on issue" event notifications in your notification scheme. As explained above, JIRA does not know the specific user who submitted the worklog, and so the user is not excluded from the email sent, however, in a particular notification scheme, you can select which users are about to receive the notification.
We are actively looking into ways to improve this.This first step will be creating a worklog tab in the issue page that displays the worklog history for the issue, but respects our permissions, so if you don't have permission to view worklogs of others, you only see your own worklog history for the issue. The worklog tab will be available in the upcoming weeks. For more information on new features, please review our Status Page.