Yes, of course one can learn from other traders and certainly every one asks questions and exchanges ideas. But most traders like myself hang on these boards for two main reasons I believe. The first reason is because trading is a very lonely profession. One cannot discuss it with non-trading friends because their eyes just glaze over and they tune out, so one comes here where others are on the same page. Secondly, more eyes means more ideas, and two heads are better than one, so one is constantly trolling the boards for the mention of a new stock with an interesting chart that meets one's personal trading criteria, or a new technique that never occurred to oneself. Certainly one learns a lot by watching and hearing what others are doing. But that is all meaningless unless one has a context in which to explain what one sees or hears, and context only comes through the development of one's own trading criteria and strategy, so one can jump on a stock mentioned that suits one's personal style and reject the one's others may make money on but are likely to lose you money. You must know the difference.
Bottomline it all comes back to the fact that one cannot succeed as a trader by coattailing others. Success only comes through hard work put in learning to trade as a special, unique individual and finding out what 'speaks' to one personally.