By scale I mean performance though I'm not sure the application's language matters as much as the SQL that's being generated and run against the database. I've just never had good luck with ORMs generating the best, most optimized SQL for the query I'm trying to run and I've known a few people who used an ORM until they started getting heavy traffic, tested out talking directly to the RDMS, found it to be more performant and end up dropping the ORM.
Don't get me wrong ORMs can certainly be performant. I just haven't seen or know anyone who used it in a manner that scaled to thousands of concurrent users and, at the same time, didn't have a lot of pain trying to do that with the ORM.