Exactly! Htiek!
When you study business they explain that demand for products is also driven by how difficult it is to obtain those products. Look at Apple's business model.
People line up when the new product comes out or pre buy the product even before it hits the market. Could they do that if they were giving away free ipads? The problem is too many artists just give away free models so people know that they don't need to buy models because they can get whatever they need for free so long as they search enough websites.
If we want to give something for free you give it to someone who deserves it not to everyone. You give something free to a customer who already bought a model as you pay it forward and want them to come back to your store. You give something free to a potential buyer who asks you directly for it by email so you can establish rapport but you do not just put it up on your site and let everyone take it.
That is damaging to you, your business and every other modelers business out there.