The FAs that do this also happen to be the same FAs that put effort into their work and care about their jobs, rather than just going through the motions as many do. Every time I have had this happen, I have had an outstanding crew and most of the time, they have done other good deeds (whether it be for me or others) that I thought worthy of writing in compliments for. I think it helps supplement a culture of striving to do more than the minimum, because people tend to care more about other people that have a name attached to them rather than just being known as seat 10A. I am 100% in support of it and hope it continues. The only time I have seen an awkward moment with this was when the person sitting next to me was upset with the FA who thanked her PM husband, but not her (she was the grumpy type that would complain about anything though).