It is impossible to secure facing forward. The seat just slides forward, unrestrained. I even demonstrated how it just slid around, but both the FA and head purser insisted "all passengers" must face forward. I refused to face it forward because since it slid forward, in the event of impact, the plane's seat belt was directly in line of my baby's neck. A severe impact would have caused the belt to cut into her neck as the car seat slid forward with my baby strapped into it. The plane's seat belt would not go anywhere. Not sure if my explanation is clear, but the bottom line is that it would have caused a decapitation.

You can also view safety videos on youtube explaining that the whiplash forces on an infant can cause an "internal decapitation" where the spine separates from the head due to the fragile nature and mechanics of an infant's body. Their heads are enormous relative to their bodies, not to mention extremely fragile. Very young infants don't even have the muscle development to hold their heads up. (This scenario is different from my own with the seat belt cutting into the neck). There are forward-facing car seats, but those are for older children.

But you're right. The infant belt loop thing is not safe, either. You can imagine the forces on the infant's fragile body and spine with the infant being thrown and jerked around in an accident or turbulence, if not crushed by the adult in the first place, as has happened. It's simply not safe.