They have all said something to the affect of "it's awkward I wish people wouldn't"
My father who was drafted during Vietnam simply said "where was my thanks when I came home"
My father was a peace and love hippy, the things the gov made him do haunt him to this day and the horrible way he was treated when he came home made it worse on him.
I have lots of love and respect for the vets of our country but I keep my thanks to myself to not make things awkward for them.