Yes, part of the appeal of expensive collectibles for me is their limited nature. There is a level of intangible value for me in knowing that there are only a certain number in the world, and that I have one. Some people like having something rare, some don't care. Personally, I enjoy it.
I have been collecting for years, and as my interests change along with my available display space, there are always pieces that I will end up selling off after years of enjoyment. I never buy a collectible for the purpose of selling, but when and if it comes time to sell, I want to know that it will hold its value. When Gentle Giant started making 20,000 of each bust, they were worth ten bucks.
You don't have to be a flipper to want your investment to hold its value. That just seems like common sense to me in the world of hobbies, and the rest of life. Whenever possible, I don't want something to be worth less than I paid--and open editions can mean that the piece won't hold its value over time. (But not always.) If I can wait and get Orthanc for less next year, then I should wait. That also means that if I run Weta and make a living selling collectibles, I don't want my potential customers holding back and waiting--if something is rare, you get it quickly before it sells out. In the long run, it's better business to keep your editions under control and weigh demand carefully. I think that's a lesson GG learned--as they overproduced their pieces, the value vanished, busts were sitting on eBay unsold at half the original price, and collectors walked away. You need a healthy level of demand for your products in the long run, and so the supply needs to be carefully controlled so the desirability stays high on the market.