Why the switch from prototypes to this.property in the constructor of everything?

This change breaks all existing instrumentation, and makes it more difficult and much heavier to create new instrumentation.

With prototypes, you only need to patch one particular function on the prototype. Building the instance purely in the constructor, you need to patch the entire code path leading up to the usage of the desired function to instrument.

I write the node instrumentation at AppNeta, and this change really sucks for me. I suspect New Relic, StrongOps and many others will be equally unhappy about it when their users start updating their driver versions and find their apps suddenly crashing.