By default, AirPort Utility on every computer on which it's installed will alert you to new firmware and other potential security issues on Apple base stations unless you disable those notices. This is also a great way to push people towards updates.
There's no central body in the hardware industry nor in most countries a regulator responsible for ensuring updates are made available and distributor. It's entirely up to the companies making it unless fraud or other criminal matters are concerned, in which case agencies like America's FTC or FCC can get involved, depending on the product, and compel updates or sue to force them.
It's a sad problem for consumers who are the victims of these practices, and I expect I'll be writing about this again and again and again until some set of collective responsibility emerges--or a sufficient liability becomes exposed.
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