I've encountered it in large enterprises (esp. public sector) that were running NetWare, eDirectory, GroupWise, Zenworks, etc., and went to SUSE (more specifically OES) as the natural follow-on from NetWare. One large organisation I'm aware of, they used to have both SUSE and Oracle Linux, and SUSE was managed by the former NetWare team, and Oracle Linux was managed by the Unix admin team and used for Oracle RDBMS and Oracle middleware.

But, in my experience, most eDirectory/GroupWise shops ended up migrating to AD/Exchange, and SUSE often went away in that process, especially if the organisation already has RHEL or Oracle Linux as well.