Heh, the people who can dabble in Assembly for a living won't be able to (typically) setup a major Web PHP + Database and all that. Assembly optimization is a different skill than web development, or other stuff in the stack.
We all gotta pick our specialties. For me, low level high-performance stuff is more of hobby project level. I got a few cool things I've learned by myself but it isn't really what I do for a living.