Current rails developer here, I've found that using ActiveRecord for basic queries and moving to SQL for more complex stuff to be a very good combination.
I agree that ORM users should learn SQL, but SQL and an ORM are not mutually exclusive.
Yep, also current rails dev here and this is also what I do :)
Learning SQL with an ORM does remind me a bit of learning memory management with a garbage collector: helps you make better choices as to how you put things together, even if you never directly use the know-how.
I agree that ORM users should learn SQL, but SQL and an ORM are not mutually exclusive.