Yes, Dormouse's last couple of posts are good. I didn't realize until lately in this thread how specialized this market was, and how confused I was about it.
True, Photo Mechanic is not a cataloger. The way I've had it explained to me from photographers is that when they take a bunch of pictures, they first browse through them using Photo Mechanic. They pick their files, sort them, do whatever they have to do to get the batch of photos they want to work with. Then, they pass those photos to a real photo editing and/or managing application like Lightroom or something. The benefit is that when you have hundreds or thousands of RAW files, you can browse through them very very quickly. In other programs, there is a slight delay while the program reads the big RAW files. Like, you have to wait for thumbnails to load, for pictures to render, etc.
So that's the workflow as I understand it from the photographers.
It sounds like if you don't have a lot of RAW files, maybe PM is not for you? Or if you're not a photographer? I don't know...