I would say the problem is both the hosts in some cases, always the guests and sometimes Airbnb.
The hosts because sometimes they don’t have measures such as CCTV or they don ‘t bother to vet their guests. Or even where they do, they don’t monitor/take action when they see more people are at the listing than have booked.
Airbnb for not working with hosts when it is clear a 🎉 is taking place to cancel the booking so a host can evict the guest.
Airbnb for refunding guests who party and whose booking is cancelled- a hosts cancellation policy should be adhered to.