If we lived in a world where housing was honestly affordable and readily available, mental health services were immediately available without social stigma, jobs were plentiful and paid a living wage, and local police departments were monitored by accountability systems which insured fair treatment for everyone, Ralph Stone might be able to make an argument for Laura's Law.
But at present, when none of those conditions are foreseeable, it is a recipe for the same discriminatory practices people in poverty see every day.
It is likely that you are violating the law by sleeping in a car or a park, or sitting on the sidewalk, or removing recyclables from a bin. It is likely that you are at the bottom of the hiring pool or the apartment applicant pool if you are disabled, or have mental health issues, or are the wrong color in a world where jobs are scarce and prejudice runs high.
It is likely that the police in your neighborhood have already made decisions about whom they would love "disappeared" from the street, or the park, or under the freeway overpass. Laura's Law enables the police to clear the streets of people. You are wrong to think it can't be you.