Few would disagree that the main function of a discussion forum is discussion. Even if the answers to a particular question or line of inquiry already exist buried in an archived thread, it seems unfair to expect any member, new or old, to be satisfied with reading through the past discussions of often unknown posters, as one would an encyclopedia.
The information received from asking your own questions is always more relevant and more personal, and there is also the bonus of being able to interact with other members. Through interacting with others, we not only experience how others see things, but we also learn a lot about ourselves.
The old threads on forums such as Dhamma Wheel and Dharma Wheel are excellent resources, but they are no substitute for personal involvement.