In ORM is an anti-pattern Laurie Voss concentrates everything I’ve been saying on the ORM plague in all these years.
If your project really does not need any relational data features, then ORM will work perfectly for you, but then you have a different problem: you’re using the wrong datastore. The overhead of a relational datastore is enormous; this is a large part of why NoSQL data stores are so much faster. If your data is relational, however, that overhead is worth it: your database does not merely store your data, it represents your data and can answer questions about it on the basis of the relations captured, far more efficiently than you could in procedural code.
I don’t really know how this article managed to elude my usually long-reaching radar for such a long time.