I totally agree, there is no need for smoking on platforms and concourse in the 21st Century. Other European countries have banned it, or at least restricted to a limited number of small areas, so why can't Switzerland? I restrict my travel on public transport as a result, forcing me to use my car (something Switzerland doesn't want me to do). If you are serious about providing the World's best public transport solution, then simply ban smoking and open up your railways to many more travellers. If you simply must allow people to smoke, provide an area that is well away from escalators/lifts/main public thoroughfares, and make the smoker feel awkward rather than the other way around.
I used to live in Tokyo. Japan is a country that's quite addicted to tabacco, but they managed to ban smoking in all public places in Tokyo, including train stations and streets. It's incredibly bothersome to wait around at the train stations here, especially with children. Smoking should be banned in all stations, period. Setup smoking rooms if necessary, for the minority who smoke and currently bother everyone else.