The Travelin Man
No, nobody says that you have to tip them now, but if this is another part of the growing trend to tip everybody, I would prefer to nip it in the bud (in my best Barney Fife voice).
I believe that there is much more than a semantic difference between a "line" cook and an "executive" chef. My personal opinion still stands that one does not tip a professional.
I am all for expressing gratitude, and I am a firm believer that doing such is one of the true lost arts of the people in this country. My feeling is that most people do not know how to express or accept genuine gratitude without it being in the form of cash.
My job requires a lot of the same skill set as a restuarant server on occasion, but with a lot more responsibility and significantly less pay. In the course of a day, I help people (customers?) make better decisions; can sway judgements in the favor; perform many dutiful tasks to make their lives simpler — all for very little thanks. I am OK with that. I have never received a tip for my services, and would never expect one. I believe that my position is a professional one, and thus not one that accepts gratuities. My only point is, when you start to think of how many people fall into that same category and who you should and should not tip, it would become cumbersome in about a minute and a half.
My belief is that a gratuity should be extended to those folks who go above and beyond in performing their duties in service fields. It is unfortunate that society deems some jobs tip-worthy and others not — and some SO tip-worthy that it is expected.