I think that the difficulty in finding a "therapist that will actually help you" is caused by the unique relationship that is the therapeutic relationship. And by that, I mean that not only do the people have to be a good match (personality, gender pref., age pref., etc.) but the person also has to have the credentials and expertise to help with the client's unique situation. The job of therapist does sound like it has a simple definition but it's also a very vague one. Every single client is unique and brings an entire life history to the table. While we all have behaviors, the basis behind each behavior varies greatly from person to person. Just because one person presents with the same symptoms doesn't mean the same therapist or therapeutic approach will be effective/a good match. In order for a therapeutic relationship to be effective, there are just so many factors that have to align.

In regards to your questions about the gray areas of long-term therapy, I think that is primarily dependent on the therapist's personal way of doing things. As far as I know, there are very few guidelines for how long a therapeutic relationship should last. The ones that do exist probably say something like, "as long as the therapy is determined to be continually effective and financially feasible for the client" (which is very subjective).