Lots of things about cooking are risky. If you ask one by one if that's really worth risking, it's tempting to say no every time, and then there's almost nothing left. It doesn't work to treat risk as a binary factor.
I think the Teflon question is different though. It is like lead in a sense, we know it is carcinogenic, just like we know lead is a neuro-poison. The only question is whether we are doing good enough job at preventing it from leaking into our bodies.
With lead, a lot of people thought so, but still they put it in our gasoline, in solder for our water pipes, etc. and a lot of people got some pretty bad neuro-developmental disorders as a result. I certainly hope we are not repeating the same story with teflon, though I, personally am not willing to risk my and my families bodies to it.
We do not know that PTFE is carcinogenic. Some of the products that can be used to make it are, but they should not be in the final product, if they are it's a manufacturing defect.
We also know that using more oil in cooking is bad, and who knows what results from the incomplete polymerization of oil and carbonized food. I'm at least as suspicious of it as I am of Teflon.
