> ... and not long ago, I increased performance of some ActiveRecord queries 1000x by simply rewriting them in SQL.

But it was ActiveRecord that got you there in the first place, as a business, and enabled you to even build anything quickly enough to meet market demand and therefore make money. Moving to a few raw SQL statements today to improve performance is called optimising and everyone in every industry does that... _after the fact_. No one should be (pre-)optimising from day 1. That's a good place to start with an ORM.

Our industry is about balancing engineering knowledge with business knowledge and market forces: we have to accept that we can't write perfect code today otherwise you won't have a job tomorrow. You have to get up and running now and optimise later, which might look like replacing some parts of an ORM's job with an optimised SQL statement.

(And again: no ORM is stopping you from running raw SQL. You can have both. It's foolish to throw out an entire ORM and everything it gives you because, "Remember when I optimised that one statement that one time?")

> I increased performance of some ActiveRecord queries 1000x by simply rewriting them in SQL. (No hate against ActiveRecord, I use it regularly. It just takes a lot of discipline once you hit queries of a certain complexity.)

ActiveRecord is the problem there, though. Or any active record-style ORM. That's why Hybernate/SQLAlchemy-style ORMs are so useful: they don't suffer from the same issues as ActiveRecord-style ORMs.