/fcam not working as intended?

[Ayat]

Exactly. There simply is no reason for why it should not and cannot be.

There actually is a reason it is clientside.

I would imagine the server doesn't actually send you the head orientation of everyone around you. Rather, the server just tells your client what they are targeting, and your client then tilts their head towards this target.

With /fcam there is no target, so making it visible to other players would require adding head pitch, yaw, and roll to the data sent from the server to each client. In an MMO even the smallest changes to network data like this are an extremely big deal, so it is unlikely they're going to add this much extra data for such a small feature.