I tend to remember my LD's with about the same frequency as I remember my memorable NLDs.

And I keep my journal because dream memories tend to fade over time (as do waking world memories, but usually faster), and I would hate to have completely lost all of the intricate details of the dreams I've had in the past. Even now, a few years after starting my journal, I look back and read amazing dreams that I have nearly forgotten all about.

It's easy to say you remember all of your dreams, at length, when you can't remember what you've forgotten. I love my dream journal, though, and I'll probably be keeping one for the rest of my life. LDing regularly has never been 'the destination' for me. I tend to enjoy the experiences more, which fade away with time, just like any other memory.