For once I am pleased with Apple's quirky business policies.
In addition to being a biohazard, enough smoking over time by many people seems to actually deposit a greassy residue on the inside of the computer parts, like the heat sinks, integrated circuits, fan blades. I used to be the IT administrator for an office of a dozen people, back when it was somehow allowed to smoke indoors in the office while you work. And the style was for everyone to smoke. As a non smoker I was a minority, and had to put up with working in that mess.
But for the computer parts, after about six months the parts looked as though someone had sprayed them with PAM cooking oil, and then dusted with ashes. All chunder stuck on fuzzy layer of dust bunnies, and "that" smell of 1000 cigarettes. We went through a lot of computers because of the lack of ability for the parts to cool themselves with the ambient air circulation inside the cases.
So my fendangled point was, it is not fair for Apple, or any computer company to have to honor warranty claims for computers that were subjected to the abuse of a smoker, as the hardware was subjected to environmental conditions that was not in any of the designed intended use. For example, if I put my computer through a dish washer, they would have the equal right to not honor my warranty claim, as I 'intentionally damaged' it in much the same way. I would like to see other companies start doing this too.. Buy a car? Did you smoke in it ? Oh, now it has no resale value, sorry.
The hardest part of climbing the ladder of success is getting through the crowd at the bottom.