At some point in your career I think it's nice to sit down with Assembly just so you understand what's going on down there. But I don't think a programmer should do that until they have a rock solid understanding of modern day programming.

The reason I say that is because modern languages have abstracted most of the direct interaction away. So a preoccupation with what's happening at the assembly level can be more of a distraction if your language of choice isn't already second nature to you.