[bobthepanda]

A bus goes through many more miles and hours of operation than the vast majority of cars. Most cars are parked for the vast majority of the day, and sometimes in covered garages.

And how long do those cameras last? The feds only fund bus replacements at twelve years or 500,000 miles.

[HPsquared]

Unlike most other parts of the bus, this part isn't mission-critical and presumably is easy to replace. It doesn't need to be made to the same durability standard as, say, the engine.