[panzagl]

It's mostly driven by publishers who want to sell books every year instead of every decade. Add some academics looking to justify their existence plus upper administrators who are given big salaries to 'do something' to 'improve' education and you soon have a system that's very willing to slosh taxpayer money around.

[Florin_Andrei]

In other words, someone has a money incentive to change the game, and the power to do it, and we're all worse off as a result.