janeainsworth is right Galen, you aren't being unreasonable and this is indeed a Health n Safety issue.
The point made by a number of people about the fact it's so easy to press the panic button, rather than lock the door or whatever in train toilets is a good one.
rubylady - I wouldn't be in a rush to hang my bag on a hook on the toilet door. In my working life, I was well acquainted with a local drug user/dealer who in desperation (frequent desperation) would go into the Ladies and put his hand over the doors, lifting numerous handbags before running off. He wasn't always caught or it wouldn't have been such a successful heist.