People come to therapy when things aren’t going well for them. Sometimes it’s an isolated thing (e.g., an unfulfilling sex life), but usually it's more pervasive than that. Either way, they are at a low confidence level. The way they have been going about things is not working; the very act of going to a therapist is often seen as confirmation of this.
Now, some helpers take advantage of this lower confidence level—they see it as an opportunity to tell the person how to live. By going to therapy, the client has forfeited the right to his or her own strategy of living, his or her own reality. It's obviously not working is what the helper communicates. Of course, this happens outside the mental health field, as well, where it can be more exploitative. It's one of the great tragedies in how we treat each other.
Good therapy understands that our mental condition is inextricably linked to our environment. None of us is happy or sad without the environment playing an integral part of that happiness or sadness. Therefore, the problem does not reside wholly in the individual—in who that individual is—but in how the individual is situated within his or her context. This perspective shifts the therapy from a I'll-tell-you-what-to-do to a Let's-understand-your-situation-first approach.