Why don't manufactures just make fire safety furniture and mattress, instead of poisioing smokers?

They do. If the only problem with smoking was that you might set your place on fire, there wouldn't be much said on this issue. Many items of furniture are treated for fire resistance but are unlikely to withstand the heat of using them to support a lit cigarette. Smoking is so bad, in so many ways that perhaps you can use this concern to quite smoking altogether.