SLES decided several years ago not to support ext4. Their reasoning was that once they started supporting ext4, they would be committed to support it for ten years (since they are an enterprise distro). At the time, they didn't have the staffing levels to support another file system, and they assumed that btrfs would be coming down the pike soon.
As it turns out btrfs took a bit longer for them to stablize than they had counted upon, but that's why they made the decision they did when SLES 11 was first released.
As it turns out btrfs took a bit longer for them to stablize than they had counted upon, but that's why they made the decision they did when SLES 11 was first released.
And now you know the rest of the story. :-)