Combine that with how the elderly are often sitting on sizable wealth while basically "giving up" on fighting battles people drag them into, and for the past several decades there has been endless lobbying by predatory sociopaths to align the law to enable this kind of behavior, because stealing money from retirees is a very easy crime to commit since they are much less likely to fight against their robbers.

Its the exact same kind of predation that produces such vile amoral policy leaps as "think of the children" turning into prescribing Adderall to every other child because they are all "hyper" while making lovely profits for the doctors and producers involved, or how "tough on crime" becomes mass incarceration of nonviolent citizens for possessing a plant where they can make private prisons ludicrous profits.

All you need is a tagline to distract the masses - "we don't want elders dying alone in their homes" and you can throw civil liberties right out the window to start making profits off them, the same way sociopaths use the legal system to pray on anyone they can.

Other failed institutions seemed at least too disinterested. That includes the police (considering all of this a civil matter), and Nevada Adult Protective Services.

Beyond that, many people (doctors, people working at retirement homes, etc) seem to have actively aided this scheme.

In general, I'd say a combination of corruption and bureaucratic apathy / CYAism are what caused this. The solution is `more accountability' but that is difficult to do without creating more potential for bureaucracy and corruption.