[Dragony]

I've thought for a while that this kind of change for the sake of change is fuelled by the number of employees in the companies involved. The ratio of developers you need to build an application vs maintaining one is huge. That creates an incentive for companies to keep building.

Out of the perspective of Agencies (Outsourcing) each working developers generates revenue. Product companies can choose to either keep their employees and keep building, or simply let a huge chunk of them go. Letting a huge number of people go (mass layoffs) is generally seen as a bad thing. So they go the other route. Keep the employees around and have them working - building new stuff.