It's a bit of sharking, but it wouldn't bother me that much. If you let things like this bother you, then there must be a multitude of other things that bother you. A well rounded pool player knows how to deal with comments like this and pretty much ignores them.
Agreed. It's not worthy of an initial response when someone tries it.
My typical greeting is, "Play well and let's have fun." But, if they use that line, all they get is, "Play well."
And, if I win, I sometimes toy with them afterwards and ""confess" something like, "Your initial sharking attempt scared the heck out of me and caused me to redouble my efforts to win. Because, when somebody I don't know says that they're usually a strong player and will stab me in the back the first chance they get."