Before blaming the physicians and therapists, consider how many people expect antibiotics for a sore throat when it is likely not bacterial, and the amount of people who attempt to find short cuts in solutions to health-related problems.
Medications serve an important role, especially for very severe mental illness (e.g., schizophrenia, bipolar, etc.), or very complex cases (e.g., dual diagnosis, complex trauma, etc.). However, if you tell someone their anxiety disorder could be 70% better in 12 weeks if they spend 1 hr twice a week with a therapist, they often balk at it. If you offer them a pill that requires zero work/effort, well that's a lot more tempting (and often more financially feasible). To be fair, it's also not even that it's laziness but a fear of having to face anxiety that can lead people to the short cut.
Then, of course, there are the physicians who are actually practicing medicine in a wildly inappropriate way who throw benzos and stimulants at people like it is $#@!ing candy.
But it is a problem that has more than one source.