Don't get conspiratorial- this is just very conservative and smart and if you think about it, why would you quibble about a $20 investment every ten years. Yes, the Americium half life is not an issue but other things might be. Electrolytic caps have lives in the 2000 hour range of continuous maximum use. LED's have output loss over time that would be significant over 10 years. Resistors have defined aging characteristics- 10 years is a long time. Even semiconductors like voltage references change over time. This assumes everything is perfect. If you live in salt air, things deteriorate faster, inexpensive IC's used in consumer goods themselves might have possibilities of contamination internally and less than infiinite lifetimes. You don't have to pitch everything but pitching safety systems makes a lot of sense especially after a decade. I have fire extinguishers in my house that I've never used thankfully. When they get to 5 years, my son and I will go out in the woods and have a great time emptying them. Did they function- of course. Should they have been pitched- of course.