Quote from cornix:
Probably three factors:
1) General. I still remember a movie "Trading Places", which I watched as a kid and which probably influenced my career choice in future. It showed some scumbags too, yes, but it was all positive, not anywhere near the modern movies, which draw the industry in very gloomy colors. Trading is not a bright dream in the consciousness of the masses anymore, maybe still, but to a lesser degree. It's almost a crime now. Sad.
2) Local. People come to trading forums to learn something mostly. Professionals may come to communicate with each other. Both sides benefit in a healthy environment, but not in environment full of negativity and trolls, which ET sadly has turned into.
3) General dilution of Internet audience. Simply more online resources appear. Some are worse, some are better, but each of them has some traffic, often leaking from other resources. Owners of "donor" resources may fight against it, but process won't stop unless there's something really unique about your resource that keeps people coming back here. So far ET still has it, but it's fading away.
I consider #2 the most important point if you ask me. Most people want to trade to make money. Tabloid format does not help this goal. Just the opposite.