Why Aren't the _construct() Methods on EAV Resources and Collections Declared as Abstract Methods?

Question

I've been poking around the bowels of Magento systems code. For "regular" model resources, Magento's _construct initialization convention has been declared abstract

File: Mage/Core/Model/Resource/Abstract.php
abstract protected function _construct();

This makes sense, as it forces developers creating their own Model resources to call the _construct function, which does the necessary initialization.

However, the same convention/need exists for EAV Model Resources and their collections, but the _construct method is not abstract in those hierarchies. Does anyone know the reasoning behind this? Are there cases where you don't need a _construct method on these models? Or is this a historical backwards compatibility thing?

Answer 1

This is left in for backward compatibility issues ;)