While i agree smoking is bad, and the user brought the problem on themselves, the product should be fit for purpose.
People smoking inside their houses is something to be expected and you can argue the manufacture should have built the product to be able to survive that.
If the situation was the same, but it was residue from the users asthma inhaler i think people would all be in agreement that the manufacture is being stupid.
I agree -- But to expect a product to live up to years of torture due to smoking and other 'unnatural' chemicals introduced into an otherwise natural environment, no, I don't think so. When things like durability of a product comes into question, it needs to be what's "reasonable". Whilst smoking in someone's private residence might be common, I don't think it's reasonable to assume household appliances, fixtures and fittings would stand up to that kind of environment for very long and still be in some kind of original condition.
I don't think an asthma inhaler has quite the same effect. Most people can puff away at an inhaler all they like (despite not suffering from asthma) and have no ill effect. I remember years ago doing tests on old breath analysis machines (the types used by Law Enforcement Agencies to test drunk drivers). It was a common misconception that asthma puffers had an effect and altered the reading (they don't), and we're talking about precise, calibrated instruments there.
On the flip side however I think it's
reasonable to assume that a person would look after their equipment, particularly if it's not sealed, has vents and fans. That includes regular cleaning/dusting and not subjecting them to harsh chemical, particulates or gaseous environments.
Based on the fact that the television in the article was purchased in 2012 and 4 years later has developed a problem (evidently due to smoking), I don't think that's unreasonable at all. Maybe if it were 3 months, yeah OK, design could have been better.