Former PC Tech opinion
I use to work for a major PC retail store as a technician and I can't tell you how many times I received computers that were malfunctioning because their owners smoked around them.
They were plain DISGUSTING on the inside with their previous white cases turned yellow and insides coated with a nasty smelling sticky tar. The smell was terrible and strong. The tar would cause fans to stop and acted as insulation, which then caused the system to overheat and parts to malfunction. I often spent more time attempting to clean the pc out then actually performing the work (which the customer should have been billed for). I felt like i should have been wearing a hazmat suit the entire time while working on them.
I agree with Apple for not performing warranty work on these systems. In my opinion smoking next to your system is just as bad as keeping your system in a damp environment where the insides can rust and corrode (which is also not covered under warranty).
Point is that people in general should be held responsible for the damage they cause to their equipment regardless what the cause is.