Conflicting Interests
If you have watched the "Wolf of Wall Street" Movie, the most significant takeaway is that people (not only stock brokers) are usually there for their own interests. When you know that a stock broker earns his pay-check by the commissions when you trade, you would have jolly well know that they will try all means to entice you to trade stocks in and out actively for their commissions to be as fat as possible.
Furthermore, they have the tendency to be slightly biased when the company is doing business with the bank they are working in too. That said, you cannot say that all of them are bad apples too. Some of them provide us with valuable and relevant stock information that are only available/accessible to them. My stock broker is one of them, everyday he sends me the forecasts and various reports.
However, ultimately I have to ......