What is currently in the database is only one 2M repeater for all of L.A. county.
Los Angeles County, California (CA) Scanner Frequencies and Radio Frequency Reference
I'm sure there are others, but haven't been submitted to the database to be added, which in turn is what the HP1 uses.
The other ham stuff is the nationwide which at least I know in my area isn't really used. So that's all your HP1 has to tune in, short of if able to get adjacent counties, I can understand why there isn't anything.
If you know of any ham repeaters in the area, submit em to us, they will be added, then you can update sentinel which in turn you can update the HP1.
Alternatively any cheap analog scanner can tune in the ham frequencies, minus shortwave, just do a ham frequency band search with it.