It really doesn't have that much to do with making the pressure cooker dangerous. The problem is with how ceramic top stoves actually work. They cycle on off to reach temperatures, sometime several times a minute. This means the surface temprature can get quite high. Aluminum (aluminium?) pans, including some brands of pressure cookers, can actually melt and leave a residue on your cooktop. This can be almost impossible to remove. Additionally, the pans used on such cooktops must be perfectly flat and in full contact with the top. Finally, some pressure cookers (the larger variety) can be quite heavy, especially if being used for canning and may cause the glass top to crack. Pressure cokkers made of stainless steel and even aluminum (we're in the U.S.) ones that are clad with other metals or made of a sandwich construction do not have the restriciton that you note for yours...