A lot of people think SQL is antiquated, and therefore not worth learning. However, SQL is based upon Relation Algebra, which is the foundation of database optimalisation. Any data querying language/library that is not based on relational algebra will lack the performance. In particular ORMs fall under this category. Having said that, there are other languages/libraries out there that do use the relational algebra constructs.
You still need to know SQL when you're using ORM. You also need to know ORM when you're using one. It's really not that hard to make ORM perform well if you spend some time RTFMing.
When was the last time your RDBMS was handling business logic and wasn't just a persistence layer for your application? SQL (the language) isn't composable so you often have a choice of building strings or having many slightly different queries.
Anyway, pros of using an ORM outweight it cons in my opinion.
