SharePoint 'Get A Link' bug?

Thanks for your replies Salvatore Biscari, Asish Padhy!

The reason I would like to disable this option is because only Key-users/Site owners should be able to manage the permissions on their sites/documents. Key users/Site Owners have the best overview of what content may be accessed by whom. If also members are able to share content with everybody else in the organization, it will become a mess because of the permission inheritance being broken. 

A customer I'm currently working for has this option enabled on all sites. But when I'll disable this option, all links sent to users in the past won't work anymore, so this will have a lot of impact.. 

Was hoping that guest links created in the past were still working and that members were only not able to create new guest links (or share content with other users) after that option was disabled. But that doesn't seems to be the case, all links are broken..