But it hasnt self-destructed, it still works on the supported platforms. The key being "supported".
In most other industries, once youve been sold the item it is no longer up to the manufacturer to keep it "up to date", beyond their legal safety requirements.
Ideally yes, but it is in the manufacturers interests to keep selling the latest models, because they get the most money with least problems and offer newer, sometimes better, features.
It really depends on how long the product has been on the market. If its more than 1 or 2 years old, then its likely to have been replaced and made obsolete.
Now, if its still their only product, then they really should work to support it.