This is one of those stupid topics in modern software development. It comes on the heals of a number of blog articles professing the many benefits of Ruby, bugs that are repaired in Rails 3.2.9, Python framework complexity.
As a professional programmer we are paid to know and understand our tools. We are expected to be efficient and productive; and from time to time we are expected to construct scalable solutions. What most programmers and managers fail to comprehend is that the efficiency usually comes in the form of macros (activerecord is essentially a very smart macro/api). The same can be said for other ORMs.