A common recurring theme in my career are horribly-performing applications because the original programmers worked with an ORM instead of the database.
Database code isn't hard! An HBM file is just as complicated as handling a data reader! Stored procedures (or in-line SQL) are simpler in the long run!
I also don't get the ORM stuff: typically you work either (1) with lots of different objects organized in some kind of document (in NoSQL sense), and you want all these objects to be predictable, free from side effects and clearly serializable to e.g. JSON, or (2) with bulk data which you transform and aggregate to come with a small collection of fully constructed (also, denormalized) objects, and for this purpose SQL is beautiful. Or else they wouldn't've invented Linq to Collections.
Database code isn't hard! An HBM file is just as complicated as handling a data reader! Stored procedures (or in-line SQL) are simpler in the long run!