When i read this on mmo-champion I just couldnt resist smiling/giving a smirk about it.We had to implement the nerf to stop some exploits where it was possible to get Demonic Circle in areas that you aren't supposed to path. We didn't want to nerf the mechanic overall and in fact we think we found a compromise where you have to either LoS OR be able to path to the location. That should cut out the exploits while still letting you use Eye to get behind a pillar or something legit.
Believe me, nothing frustrates us more than having to nerf something because of 'sploiters.
It's sad that it going away but to be honest i had so much fun exploring with it.