We've discussed the timeshare companies on here previously. I fully expect this will likely get moved by a mod to that thread if the discussion continues, but in the meantime I feel compelled to respond.
Firstly as disclosure - two of my close relatives have shares in Wyndham, and a friend of mine does too. My most recent trip to Disneyland Resort was at the Worldmark Anaheim (affiliate through Wyndham) and I can honestly say it was fantastic.
The thing is - people don't go into these things with eyes open. Your link to Wyndham refers to it repeatedly as a scam, and they (and i'm sure anyone who knows how to use google) found countless reviews, blogs and complaints about their process... however this link also says:
...and that's the problem of the consumer. The sales tactic is legitimate. The ACCC have investigated complaints about this style of marketing and selling and found it to be in accordance with the trade practices act. People attend these 'seminars' willingly, lured by the promise of a free hotel stay, discounted tickets or small gifts. I can't comment on Ultiqa - never seen or heard of them, but Wyndham's tactics are well known, and totally legal.
Anyone who signs a contract without reading it is an idiot, deserves everything they get and receive no sympathy from me. All one has to do is watch Judge Judy or The People's Court to see the same old story about how someone didn't read their contract properly.
As for their appearance in the theme parks... i'm sure they pay handsomely for the privilege. The parks therefore get a revenue stream from it which allows them to buy other things we want. If you aren't interested in it, or think its a scam - a simple no thankyou, or walking on the opposite side of the path is the end of the interaction with them.
If you do attend a seminar, its usually because either: 1) you're interested in what they're selling; or 2) you want something for free, which is what they promise to give you if you come.
Either way - you attend because you want something out of it. They offer the free things to you to get you there. Its the cost of marketing. They could buy TV ads costing thousands, or they could purchase tickets from the theme parks wholesale and then offer them at a substantial discount.
Bottom line - don't like them, don't go, but don't go, and then complain that about how you wasted 2 hours of your time, or were pressured into buying from them - thats the price of the free tablet computer \ discount tickets. Nothing is free in this world.