Obviously it's hard to speak to specifics, and I would be lying if I said that there were no incompetent physicians or nurses out there, but from my end I've seen even veteran ER physicians struggle to get psych to admit patients to their service. Psych is incredibly overworked and understaffed for the volume of patients they get, and sometimes they triage based on their best assessment of an incomplete picture in a way that produces less than satisfying outcomes.
At the end of the day, they need a place to go, and if there aren't enough beds to go around then it doesn't matter whether or not they believe you, or me, or the patient themselves. They'll end up right back out in the streets.
If you're into long, dry, position statements,
this is a good read, as is this
powerpoint.