I can tell you why 'unsuccessful' traders are on this site.
I do not consider myself unsuccessful as I do not consider myself a trader yet, even though I have been 'dabbling' for approx 18 months.
It has taken me all this time just to find instruments that I am at ease with and have only just started real trading them, bit of a roller-coaster at the moment, but I will give it time.
However, from my point of view, the main reasons I use this site is for the completely unbiased advice you get, no matter how basic the question, nor are newbies made to feel stupid, something which can happen easily on other sites.
I have asked questions ranging from technicalities to absolute total trading basics and have always had a courteous, understandable and constructive reply.
I would urge all newbies to ask their questions and not be afraid to look silly.
When this site is down it's like losing an arm