Why is it always timeshares? What makes them so ideal to sucker people with? I've seen these scams all over the world.
That said, there is nearly no game or investment that doesn't at least have some people trying to cheat others.
There are plenty of good management companies that run thousands of timeshare units. My family pays for 3 and all are in perfect shape, own private beach access, gives access to nice cars (that are changed to new every 2 years) and have very strict rules on participants. No, you cannot just crash place with your friends and call the day; the penalties are harsh and good timeshare management will match you with people interested in similar lifestyle. They are much much cheaper than price of tickets / setting up vacation trip and the thought alone that maximum 52 people (versus 365 in hotel room) per year slept in that bed and took a dump in that toilet is a very comfortable one :)
They're as expensive as a car, but sold (a) remotely (so the customer has no opportunity to inspect before buying) and (b) within a vacation mindset (which makes people less diligent about diligence). TL; DR Used car salesmen with fewer checks on their behaviour.