So some?all? european railways do not like to have passengers get out in places that are not station platforms for safety (probably insurance) reasons because people are idiots.
So much do they not want passengers to get off that they let me smoke on a DB Train last year in Germany 2016 when the diesel train I was on broke down and we were stranded for a while. We were having a smokers riot and just wanted to step out for a smoke, the conductor and engineer said no - but finally conceded to open 1 door and just have the smokers huddle around it and blow out the door.
But it seems to me they should correct the fire system instead tell them to ignore it. I think it is a very bad idea to teach people to ignore a fire supression system!
When I encounter someone smoking I assume that they are on fire and deal with it appropriately.
Last summer some religion peddler came up my driveway smoking while I was out watering the flowers. I dealt with his problem. A light misting only I assure you.
If you think you are too small to make a difference, try sleeping with a mosquito.
Dalai Lama