Depends on what kind of optimizations, and on the ORM I guess. The major problems described in the article, like n+1 queries and filtering on the client rather than in the database seem to be easier to fix in an ORM than in hand-written SQL with boilerplate wrappers. (Of course they are also easier to introduce in an ORM if you don't know what you are doing, but such is the curse of powerful abstractions.)

Even things like query hints can be easily applied in the ORM's I know. It is kind of hacky since it breaks abstraction layers - but so is query hints in SQL.

But of course there can be some special cases where you just have to drop down to raw SQL for some reason. All ORM's I know allow this.