Each novice trader asks such a question. And, having studied several pages proposed by the search engine, he decides that the broker is breeding it for money, forcing him to lose deals. This is actually not the case.
The broker must maintain balance - it is necessary to have a sufficiently large percentage (35-40%) of successful traders. This helps to attract new people who want to try on the profession of a trader. Of course, the broker is not a charity and has profits from any transaction, both winning and unsuccessful.