The only times I was personally greeted were on CX (90% of the time), and once on QF when I was in F.

The only times I wasn't greeted on CX were when the cabin was full. I did notice one time that the CX manager didn't greet everyone - those that were flying on non-CX flight numbers.

It's certainly nice being greeted, but it's no big deal really. I tend to keep to myself and observe whether I'm travelling by myself or with others.

P.S. I was a SG at the time.