The party in California was not large. The house is a 3 story mansion. It looked like a sparsely attended party to me. Only 100 people, it certainly wasn't big. It had a DJ and a food truck showed up. No one in that neighborhood would complain.
True only 100 people but as the article states there were 50 cops which on would assume had better things to do.
If they can afford 50 cops to break up a house party there are too many cops.
Understand what you are saying, based on what most people think cops do the most of, but most of my interactions with police have in-fact been about taxation supposedly to affect behaviors, but often just to generate revenue, so quite often, just tax collectors, ie, speeding, public yet peaceful intoxication, city sticker or plates out of date, etc. They generate a lot of money. Some communities use speed traps effectively to augment the tax base funds. if big enough, a peaceful house part is much easier to generate fines faster and more efficiently at less operational expense of fuel and wear and tear on equipment and police officers than than speeding tickets and a heck of a lot less than wading into a riot. Just the ticketing process at a house party offers much better opportunity for more and greater fines, when just finding out who is in there often offers up people already wanted for other unpaid offense debts. For the public good health and the public coffers, they are a very attractive nuisance, that is a new income stream.