That is covered in the article. ORMs are an advantage in the very early stages of a project, but a disadvantage in the later stages. Since a project by definition spends the least amount of its lifetime in the early stages, don't paint yourself into a corner!
For most of my projects I use Django nowadays. Its ORM is usually sufficient. In cases where it is not I add a query method to a model class that just executes the most efficient sql query possible and returns the results in the most efficient format possible. For mature applications this can result in quite a lot of those query methods and the ORM than plays a lesser role.
However, even in those case the ORM continues to be a convenience to me as a developer, e.g. because it powers the Django admin interface and because together with South (a database schema migration tool) it makes schema management a breeze.
An ORM is a tool. And each tool has its own place and time. So, yes - there we go again ...
Thanks for mentioning this. I'm just learning Django, mainly for using its admin interface to avoid a lot of CRUD, and South seems just what I need to evolve my schema while I go along.
Said developers will never take the next step of swapping out bad ORM-generated SQL for good hand-tuned SQL. The app is therefore doomed.