Canning on a Glass Top Stove

We are aware that some warn against using an All-American Pressure canner on a glass top stove. We have used our canner on our galss top stove for some 12 years without problems. Then why do they advise against it? We suspect it is due to our litiguous society where any problem we face is someone's problem to fix for us. We also suspect that they want to play safe so if you drop your canner on the stove then you can sue and claim the canner is the problem and they must fix the problem. We will continuee to use the canner on our glass top stove as we have done for these past years.